Indigestible dextrin

ABSTRACT

An indigestible dextrin characterized in that the dextrin contains: 
     (A) up to 50% of 1→4 glycosidic linkages, and 
     (B) at least 60% of an indigestible component, 
     (C) the content of indigestible component as actually determined varying within the range of ±5% from a value Y calculated from at least one equations, i.e., Equations 1 to 30, given in the specification, 
     (D) the indigestible dextrin being prepared by adding hydrochloric acid to potato starch and heating the potato starch at 120° to 200° C. using an extruder, 
     the value Y being a calculated content (%) of the indigestible component.

BACKGROUND OF THE INVENTION

1. Field of the invention

The present invention relates to indigestible dextrin prepared by heat-treating potato starch with addition of an acid.

2. Description of the Prior Art

Heat-treated starch (pyrodextrin) is prepared by heating a starch containing several percent water in the presence or absence of an acid. The glucose forming the starch consists primarily of 1→4 and 1→6 glycosidic linkages with very few 1→3 and 1→2 glycosidic linkages as is already known.

The proportion of these glycosidic linkages are disclosed only in J. D. Geerdes et al., J. Am. Chem. Soc., Vol. 79, 4209(1957), G. M. Christensen et al., J. Am. Chem. Soc., Vol. 79, 4492(1957) and the literature mentioned below. Commercial potato starch as heated-treated with addition of hydrochloric acid comprises at least 57.3% 1→4 glycosidic linkage fraction (2,3,6-Tri-O-Methyl-D-glucose), 2.6% 1→6 glycosidic linkage fraction (2,3,4-Tri-O-Methyl-D-glucose), up to 1.2% 1→3 glycosidic linkage fraction (2,4,6-Tri-O-Methyl-D-glucose), and 6.3% of a fraction having both 1→4 and 1→6 linkages (2,3-Di-O-Methyl-D-glucose).

R. L. Whistler and E. F. Paschall, Starch Chemistry & Technology, Vol. 1, p. 430(1965) makes reference to analyzed values of linkage types constituting heat-treated amylopectin and heat-treated amylose obtained by separating corn starch into amylopectin and amylose fractions and individually heating the fractions with addition of an acid. The analyzed values obtained for the heat-treated fractions were prepared by gelatinizing corn starch, then separating the starch into the two fractions and heating each fractions. The crystalline structure of powder heat-treated thus differs from that of natural starch, so that the values can not be directly used for comparison. However, in view of the fact that the ratio between the two fractions of usual corn starch is about 8:2, the analyzed values, when calculated for corn starch correspond to 67% 1→4 glycosidic linkage fraction (2,3,6-Tri-O-Methyl-D-glucose), 2.7% 1→3 glycosidic linkage fraction (2,4,6-Tri-O-Methyl-D-glucose), and 7.8% a fraction having both 1→4 and 1→6 linkages (2,3-Di-O-Methyl-D-glucose).

U.S. Pat. No. 2,274,789 discloses a prior-art process for preparing heat-treated starch and an apparatus therefor. This patent discloses a continuous treatment wherein hydrochloric acid is continuously added to a starch with a water content of about 45%, the starch dried in the form of a fluidized bed, heated at 105° to 260° C. and cooled to obtain a product of stable quality free of the hazard of explosion.

U.S. Pat. No. 2,332,345 discloses a process wherein starch is heated at 120° to 176° C. with stirring in a cylindrical container equipped with a steam jacket to obtain a product which has excellent properties as to adhesion, body smoothness of paste, stability and permanence of paste fluidity and shortened time of drying.

U.S. Pat. No. 2,565,404 discloses a process for preparing a starch sugar easily by adding hydrochloric acid to a powdery or wet starch, heating the starch to about 100° C. in an autoclave equipped with a stirrer while introducing a gas into the autoclave and heating the starch to about 130° C. with introduction of steam.

U.S. Pat. No. 2,698,818 discloses a process for preparing a product having a high quality over a wide range by drying starch in a vacuum within an autoclave with stirring and heating, and further heating the starch to 168° C. in a vacuum with introduction of hydrogen chloride gas.

U.S. Pat. No. 2,818,357 discloses a process which comprises adding hydrochloric acid to starch, then feeding the starch into a heated spiral coil, and heating the starch to 115° to 160° C. within a short period of time while moving the starch through the spiral coil by vibrating the coil, whereby a uniform product is continuously prepared with a high thermal efficiency.

U.S. Pat. No. 2,845,368 discloses a process wherein vaporized hydrochloric acid is added to starch while the starch is being fluidized by introduction of a gas so as to react the starch under widely varying conditions by heating the starch in the fluidized state within a short period of time.

U.S. Pat. No. 3,200,012 discloses a process comprising adding hydrochloric acid to starch in the form of fine particulate and feeding the starch into a rotatable drum internally provided with a heating tube to heat the starch and continuously obtain a product having a diminished reducing sugar content and good solution stability.

Furthermore, Tomasik, P. and Wiejak, S., Advance in Carbohydrate Chemistry, Vol. 47, 279-343(1990) generally describes the latest information as to heat-treated starches.

When analyzed, the products of the foregoing processes were found to contain up to 30% indigestible fraction. When starch was heated under altered conditions to obtain a higher indigestible content, it was possible to increase the content to about 60%, whereas the product then contained an increased amount of colored substance, had a stimulative odor, therefore required purification, and was not practically useful because of extreme difficulties encountered in refining the product. Accordingly, the conventional processes fail to afford a product which contains about 60 to 90% indigestible fraction as contemplated by the present invention.

As to the decomposition of carbohydrates with use of an extruder, U.S. Pat. No. 4,316,747 discloses a process wherein a cellulose slurry containing an acid added thereto is heated in a twin-screw extruder under an increased pressure to prepare glucose.

With improvements in living standards in Japan in recent years, eating habits have changed and become similar to those of American and European people. This trend has resulted in a lengthened average life span and a rapidly aging society with marked increases in degenerative diseases. Manifestly, people have become health-oriented. Attention has, therefore, been directed to dietary fibers and oligosaccharides enhance the function of foods and livestock feeds in that these materials are known to alleviate constipation and other desired biological regulatory functions.

Indigestible substances, such as dietary fibers and oligosaccharides, exhibit various modes of behavior in the digestive tracts producing physiological effects on the living body. First in the upper digestive tract, water-soluble dietary fibers slow the transport of food and delay the absorption of nutrients. Delayed absorption of sugar, for example, suppresses the rise in blood sugar value, consequently lowering insulin requirements. Further, excretion of bile acid is promoted, diminishing the sterol group in the body lowering the cholesterol level of the serum. Other physiological effects through the endocrine system of the body are also reported.

Another feature of these indigestible substances is they are not digested or absorbed by the digestive tract, including the small intestine and reach the large intestine. On reaching the large intestine, oligosaccharides and dietary fibers are partly acted on by enterobacteria yielding short-chain fatty acids, intestinal gases, vitamins, etc. Acidification of the intestinal environment by the short-chain fatty acids condition the intestine. It has also been reported that when absorbed, these short-chain fatty acids are metabolized to provide energy and, simultaneously, inhibit the synthesis of cholesterol. Therefore, ingestible substances are necessary in obtaining these desired physiological effects.

A "dietary fiber hypothesis" suggested by Trowell and Burkitt epidemilogically revealed that there Is a negative correlation between the intake of dietary fibers and the onset of non-infectious diseases such as cholelithiasis, ischemic heart diseases, cancer of the large intestine, etc. Thus, insufficient ingestion of dietary fibers is thought to be a cause of degenerative diseases which are said to be diseases of the Western type. The dietary fibers are defined as the "whole group of indigestible components of foods which are not digestible by human digestive enzymes" and are classified into insoluble dietary fibers and water-soluble dietary fibers according to the solubility in water. Of these, water-soluble dietary fibers have attracted attention as materials for functional foods and livestock feeds because of their great physiological function.

For example, it is said that high viscosities inhibit diffusion of sugar, resulting in delayed absorption of sugar and reduction in the rise of blood sugar value, consequently lowering insulin necessity. Further it is said that promoted excretion of bile acid into feces by water-soluble dietary fibers diminishes cholesterol in the serum, and that after reaching the large intestine, the dietary fibers are acted on by enterobacteria to produce lactic acid and acetic acid with these organic acids lowering the pH within the large intestine and preventing cancer of the large intestine.

Examples of such water-soluble dietary fibers include guar gum, glucomannan, pectin and like natural gums which have high viscosity which are difficult to ingest singly in a large amount. Further the addition of these fibers to processed foods encounters problems in preparing the food and presents difficulties with respect to texture. It has therefore long been desired to provide dietary fibers of low viscosity which have the same physiological functions as the above fibers, are easy to ingest and are user-friendly in preparing processed foods.

In recent years in Japan, processed foods, precooked foods, fast foods and the like have found wider use with the maturity of economical environments and the resulting improvements in food processing techniques and distribution techniques. With this trend, diversified information as to the ingestion of foods has become available, and eating habits to fulfill the nutrient requirements are changing to health-oriented dietary habits contemplated for the prevention of nutrition disorders and degenerative diseases due to eating habits. Especially, people of middle or advanced age and young women have much need for low caloric foods, so that low caloric sweeteners and bulking agents for strong sweetening agents have been developed. Among these, low caloric sweeteners include various indigestible oligosaccharides and sugar alcohols, which nevertheless have many problems with respect to the quality, degree of sweetness, oligosaccharide content and likelihood of causing laxation.

The bulking agent available for use with strong sweetening agents such as aspartame is polydextrose only, whereas polydextrose is ingestible in a limited amount, tastes bitter in an acid condition, is hygroscopic and therefore has problems. In view of the situation described, it has been desired to provide a low caloric bulking agent which fulfills the requirements for use as a food and which is usable for sweeteners and the like with safety.

On the other hand, starch is used in large quantities in various processed foods as a food material. Useful food materials of these types include starch and starch products such as pregelatinized starch, pyrodextrin, derivatives, glucose, corn syrup solids and maltodextrin. However, a majority of these starch products are not higher than 5% in the content of indigestible component and at least 3.9 kcal/g in caloric value, so that among starches and like materials, only pyrodextrin appears useful as a dietary fiber and low caloric material. Heat-treated starch (pyrodextrin) will hereinafter be referred to merely as "dextrin".

We conducted continued research on processes for preparing dextrin, starch hydrolysis processes and processes for preparing indigestible dextrin from dextrin. Based on the results obtained, we have already filed a patent application for an invention entitled "Process for Preparing Dextrin Food Fiber". Our research, subsequently carried out on the physiological activities of the dextrin, revealed that the dextrin had an improvement in intestine conditions, amelioration in hypercholesterolemia, a lowering insulin requirements, a hypotensive effect and a lower caloric value, i.e. effects similar to those of dietary fibers. Based on the finding, we have filed a patent application for the dextrin as a food composition.

We have also investigated the correlation between the structure of dextrin and the content of indigestible fraction thereof and found that the content of indigestible component of dextrin is in inverse proportion to the amount of 1→4 glycosidic linkages of dextrin among other glycosidic linkages thereof. We have further conducted detailed research.

The research thus conducted on various dextrins indicates that the indigestible component is closely related with the quantities of 1→4, 1→6 and like glycosidic linkages, and statistical numerical analyses afforded equations representing a high degree of correlation there-between.

With the prior-art reaction conducted at atmospheric pressure, the velocity of reaction is a function of the time and temperature, i.e., reaction conditions, whereas the heat treatment of starch under increased pressure is entirely different from the conventional reaction in that the correlation between 1→4 and 1→6 linkages and the indigestible fraction can be expressed by a special function, i.e., equation. This is a novel finding we obtained. Nevertheless, the dextrins obtained by conventional techniques are as low as 5 to 30% in the content of indigestible component, contain a colored substance or release a stimulative odor even if obtained by a high-temperature long-time reaction, and are in no way actually usable.

SUMMARY OF THE INVENTION

Accordingly, the main object of the present invention is to provide a novel indigestible dextrin containing at least 60% of indigestible component and diminished in colored substance or stimulative odor.

This object can be accomplished basically by providing a dextrin which contains an indigestible component in an increased amount of at least 60%.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph showing the relation between the temperature of various substances and the viscosity thereof;

FIG. 2 is a graph showing the relation between the reaction time of various substances and the degree of coloration thereof;

FIG. 3 is a graph showing the relation between the reaction time of various substances and the degree of coloration thereof;

FIG. 4 is a graph showing the relation between the number of freeze-thaw cycles and the turbidity;

FIG. 5 is a graph showing the relation between the concentration and freezing point depression;

FIG. 6 is a graph showing the relation between the moisture content of indigestible dextrin and the time during which the dextrin is allowed to stand at a predetermined relative humidity;

FIG. 7 is a mixogram of a control group;

FIG. 8 is a mixogram of a sugar group; and

FIG. 9 is a mixogram of indigestible dextrin group of Example 6.

DETAILED DESCRIPTION OF THE INVENTION

The analytical data given herein is expressed as data as to anhydrous substances, while values as to water-containing substances are given in Examples of food and feed, unless otherwise specified. And dietary fiber and caloric values of foods and feeds component other than indigestible dextrins are calculated values according to "Standard Tables of Food Composition in Japan" 4th revised Ed., (1982), Resources Council, Science and Technology Agency, Japan. Also the glucose residue composed solely of 1→4 bonds is expressed as "glucose residue having 1→4 bonds" further, 1→6 and 1→3 bonds are expressed as above.

The starch to be used as a material for indigestible dextrin according to the invention is potato starch, and the treatment to be conducted essentially requires addition of an acid to the starch as a catalyst. While various acids are usable, hydrochloric acid is especially desirable to use since the product is used for foods. The indigestible dextrin obtained must contain at least 60% of an indigestible component, as required for the dextrin to exhibit biological regulatory effects.

Incidentally, dextrins include white dextrin which has heretofore been generally used for foods and medicines. This dextrin contains about 5% of indigestible component and therefore is not usable for applications wherein biological regulatory effects are required. Further conventional yellow dextrin, when containing at least 30% of indigestible component, has a stimulative taste and is accordingly unusable.

Examples of apparatus desirable for use in the process of the invention for conducting heat-treatments under a high pressure are extruders for use in preparing snack foods and the like.

Twin-screw extruders are most desirable to use.

Extruders, which are used for extruding materials under an increased pressure, are divided generally into those having a single screw rotatably inserted in a cylinder, and those having two screws rotatable in the same direction or reverse direction and inserted in cylinders arranged in the shape of the FIG. 8 in cross section. Although extruders of either type are usable in this invention, twin-screw extruders are especially preferred. The screw or screws are generally demountable, and can be of various types with respect to the pitch, including reverse pitch type. Screws of varying pitches can be used in a suitable combination. With some extruders, suitable screws are selectively usable in accordance with the properties of the material to be treated. Usually, the material is fed to the extruder at one end of the screw in rotation with the cylinder heated, and is treated as heated under an increased pressure while also utilizing the heat of friction between the screw and the material.

Extruders of either type are 30 to 340 mm in the diameter of the screw and about 10:1 to about 45:1 in the ratio of the length of the screw to the diameter thereof. The extruder is heated with steam or by electric or induction heating. The actual operation of the extruder requires a material container, material feeder, product cooling device, product transport device, product container, etc.

The extruder (either of the single-screw or twin-screw type) is operated heated at 120° to 200°. Further to use the extruder as a reactor, it is essentially required that the material and the product be smoothly movable through the extruder. The rotating speed of the screw is closely related also with the properties of the material, heating temperature, reaction time and the amount of acid added, and must be optimally determined based on the content of indigestible component of the product. Usually, it is 120 to 400 r.p.m.

Hydrochloric acid is used in the form of an aqueous solution having a concentration of about 1%, and is added to the material starch in an amount of 3 to 10 wt % based on the starch. Since the acid solution is added to the starch before the heat treatment, the solution and the starch are mixed together uniformly by being stirred in a mixer and aged therein. The mixture is then preheated at about 100° to about 120° C. to a water content of about 8% which is slightly higher than is the case with the prior-art heating process using atmospheric pressure. The material is thereafter continuously fed to the extruder for heat treatment, and the product discharged from the outlet of the extruder is rapidly cooled to complete the heat treatment.

The heat treatment by the extruder is most distinctly characterized in that starch is continuously reacted in a molten state. Whereas the starch as heat-treated by the conventional method remains in the form of a powder despite the treatment, the starch as heat-treated in a molten state is in an amorphous form.

Higher reaction temperatures result in increases in the content of indigestible component, but very high temperatures are not desirable since the product contains an increased amount of colored substance when the temperature exceeds about 170°. Stated specifically, the reaction temperature is 120° to 200°C., preferably 130° to 180°C., more preferably 140° to 180°.

For a better understanding of the features of the present invention, experimental data will be described below in detail.

EXPERIMENTAL EXAMPLES

1. Method of Determining the Content of Indigestible Component

The content was measured by a modified method according to "The method for determining the indigestible part using HPLC" (Journal of Japanese Society of Starch Science, Vol. 37, No. 2, p. 107, 1990) as will be described below.

One gram of a sample was accurately weighed out, and 50 ml of 0.05M phosphate buffer (pH 6.0) was added to the sample, followed by addition of 0.1.ml of Termamyl (alpha-amylase, product of NOVO Industry Co., Ltd.) and reacted at 95° C. for 30 minutes. The reaction mixture was cooled and adjusted to a pH of 4.5. A 0.1 ml quantity of amylo-glycosidase (product of Sigma) was added to and reacted with the mixture at 60° C. for 30 minutes, followed by heating to 90° C. to complete the reaction. The resulting mixture was diluted to 100 ml with water, and the amount of glucose produced was determined by the pyranose-oxidase method. The content of indigestible component was calculated from the following equation.

    Content of indigestible component (%) =100 -Amount of glucose formed (%)×0.9

2. Method of Quantitatively Determining Glycosidic Linkages

A sample was methylated by a modified method of Hakomori's methylation method (S. Hakomori, J. Biochem., 55, 205(1964)) described below, followed by hydrolysis and thereafter by gas chromatography to quantitatively determine the glycosidic linkages composing the sample.

(1) Methylation

A dehydrated sample (100 to 200 μg) is placed into a test tube (15 mm diam.×100 mm) with a screw cap and dissolved by addition of 0.3 ml of DMSO. To the solution is added 20 mg of NaH, immediately followed by addition of 0.1 ml of methyl iodide. The mixture is stirred by a touch mixer for 6 minutes and then cooled in ice water, and 2 ml of water is added to the mixture. The mixture is fully shaken with addition of 2 ml of chloroform. The upper layer (aqueous layer) is collected with a pipette and discarded. The remaining layer is similarly washed with addition of 2 ml of water. This procedure is repeated 6 times. Cotton is placed on the bottom of a Pasteur pipette, anhydrous sodium sulfate is placed into the pipette to form a 4- to 5-cm-thick layer, and the solution is passed through the layer for dehydration and then washed with chloroform. Subsequently, the solution is concentrated to dryness in a rotary evaporator.

(2) Hydrolysis

With addition of 0.5 ml of trifluoroacetic acid, the methylated product is hydrolyzed at 100° C. for 4 hours, and the hydrolyzate is concentrated to dryness at 60° C. in a rotary evaporator.

(3) Reduction

The hydrolyzate is dissolved in 0.5 ml of water, and the solution is allowed to stand at room temperature for 2 hours with addition of 10 mg of sodium borohydride. Several drops of acetic acid are added to the mixture until the mixture ceases forming to terminate the reaction. The mixture is then dried at room temperature and further dried at room temperature with addition of 1 ml of methanol to remove the boric acid formed. This procedure is repeated 6 times.

(4) Acetylation

With addition of 0.5 ml of acetic anhydride, the reduced product is heated at 100° C. for 4 hours and thereby acetylated. With addition of 1 ml of toluene, the product is concentrated to dryness in a rotary evaporator.

(5) Desalting

The acetylated product is dissolved in 1 ml of chloroform, the solution is shaken with addition of 1 ml of water, and the aqueous layer is discarded. After repeating this procedure 5 times, the chloroform is evaporated off from the resulting layer by a rotary evaporator.

(6) Dissolving

The desalted product is dissolved in 0.5 ml of chloroform and subjected to gas chromatography.

(7) Conditions for gas chromatography

Column: DB-1 fused silica capillary column 60 m×0.255 mm I.D., 0.1 μm film

Column temperature: 50° C. for 1 minute, elevation of temperature at a rate of 10° C./min to a constant temperature of 280° C.

Temp. of sample vaporizing chamber: 300° C.

Detection temp.: 300° C.

Flow rate: 2.5 ml/min, helium

Detecting unit: flame ionization detector

3. Method of Quantitatively Determining Dietary Fiber Content

Dietary fibers are quantitatively determined by the following Prosky method (No. 985.29, Total Dietary Fiber in Foods, "Official Methods of Analysis", AOAC, 15th Ed., 1990, P.1105˜1106, No. 985.29, Total Dietary Fiber in Foods).

4. Method-1 of Measuring caloric Value

According to the following method titled "Measurement of Physiological Combustion Heat of Food for Specified Health Use Containing Water-Soluble Low Calorie Sugars" which is notified by the Ministry of Health and Welfare of Japan.

4-1. Reagents and others

(a) Somogyi reagent

90 g of Potassium sodium tartrate and 225 g of sodium tertiary phosphate (Na₃ PO₄ ·12H₂ O) is dissolved in 700 ml of distilled water, and 30 g of copper sulfate (CuSo₄ ·5H₂ O) and 3.5 g of potassium iodate (KIO₃) are added to the solution. The resulting solution is diluted to 1000 ml with distilled water.

(b) Lawry reagents

Solution A: mixture of 1% copper sulfate (CuSO₄ ·5H₂ O) solution and 2.2% potassium sodium tartrate solution at a ratio of 1:1

Solution B: mixture of phenol reagent and distilled water at a ratio of 1:0.8

(c) Sugar alcohol measuring kit

F-kit: F-kit D-sorbitol/xylitol, product of Boehringer Mannheim Yamanouchi Pharmaceutical Co., Ltd.

(d) Diastase Solution

2% solution of diastase (Japanese Pharmacopoeia).

(e) Hydroxylamine pyridine solution

Solution of 100 mg of hydroxylamine in 10 ml of pyridine.

(f) Condition for gas chromatogrphy

FID gas chromatograph, 5% SE30 chromosorb W, glass or stainless steel column measuring 3 to 4 mm inside diameter and 2 m in length, column temperature 185° C., carrier gas 80 ml/min.

4-2. Determination of total water-soluble reducing sugar

(a) Preparation of test solution

Oligosaccharides are thoroughly extracted from the sample using water or 89% ethanol when the sample contains only oligosaccharides or using 80% ethanol when the sample contains starch and like polysaccharides. The extract is concentrated under reduced pressure (at not higher than 60° C.), the residue completely dissolved in a small amount of 50 mM maleic acid-Na buffer (pH 6.0), and the solution adjusted to a glucose concentration of about 500 mg %.

(b) Procedure

To 1 part of the test solution is added 2 parts 1N hydrochloric acid, and the mixture heated in a boiling water bath at 100° C. for 20 hours. The reducing sugar of the resulting solution is determined by the Somogyi method, and penrose and hexose alcohols therein by gas chromatography or F-kit. The combined amount of carbohyrates determined is taken as the amount of total water-soluble saccharides (A).

(c) Somogyi method

2.5 ml of somogyi solution is added to 7.5 ml of test solution (1 to 10 mg, calculated as reducing sugar), and the mixture is heated at 100° C. for 10 minutes, cooled and then thoroughly mixed with 2 ml of 2.5% of potassium iodide (KI) solution and 3 ml of 2N sulfuric acid. The mixture is titrated with 1/40N sodium thiosulfate (Na₂ SO₃ ·5H₂ O). Glucose is used as a standard saccharide. The sugar content of the test solution is determined from the titration value obtained.

(d) Determination of sugar alcohol

The test solution hydrolyzed for the determination of total water-soluble sugar is suitable diluted and used to measure the amounts of sorbitol and xylitol by F-kit.

In case the solution contains pentose or hexose alcohol other than sorbitol and xylitol, gas chromatography is used. The test solution hydrolyzed for the determination of total water-soluble sugar is concentrated under reduced pressure at a temperature of up to 60° C.; ethanol is added to the concentrate so as to give a final concentration of at least 80%, and the mixture is heated in a boiling water bath for 30 minutes for extraction. The extract obtained is concentrated under reduced pressure at no higher than 60° C. To the concentrate is added 80% ethanol to obtain a predetermined amount of solution. A 5 ml portion of this solution is collected, from which the solvent is completely removed under reduced pressure. The residue is dissolved in 1 ml of pyridine; 1 ml of hydroxylamine pyridine solution is added to the solution, and the mixture is allowed to stand for 5 minutes and thereafter distilled under reduced pressure to remove the solvent. With the addition of 1 ml of benzene, the residue is treated under reduced pressure to completely remove water, and the resulting residue is dissolved with 2 ml of pyridine. To the solution are added 0.2 ml of hexamethyldisilane and 0.1 ml of trimethylsilane, and the mixture is allowed to stand at room temperature for at least 15 minutes, thereafter adjusted to a predetermined amount with pyridine and subjected to gas chromatography to quantitatively determine sugar alcohol by the absolute calibration curve method.

4-3. Determination of insoluble starch

As to samples containing starch, the sample used corresponds to 2.5 to 3.0. g dry weight resulting residue from extraction with 80% ethanol in the same manner as the extraction of total water-soluble sugar. The residue is dispersed in 200 ml of water, and the dispersion is heated in a boiling water bath for 15 minutes while being continuously stirred, followed by cooling to 55° C. and addition of 10 ml of diastase solution. The resulting mixture is allowed to stand at 55° C. for 1 hour, then boiled for several minutes and thereafter cooled to 55° C. again, followed by addition of 10 ml of diastase solution, continuous stirring and standing for 1 hour. When the substance remaining in the resulting reaction mixture is found positive by iodine-starch reaction, diastase solution is added to the mixture once again for further digestion. If the solution as treated with diastase proves negative when checked by iodine-starch reaction, the solution is diluted to 250 ml with distilled water, then filtered with filter paper. Hydrochloric acid is added to the liltrate to a concentration of 2.5%, and the mixture is heated in a boiling water bath for 2.5 hours, cooled, thereafter neutralized with 10% sodium hydroxide solution and filtered. The liltrate is suitably diluted and used for the determination of glucose by the Somogyi method. The amount of glucose thus determined is multiplied by 0.9 to obtain a value which is the amount of starch (A').

4-4 Determination of sugars digested and absorbed by the small intestine.

(a) Determination of enzyme-digested sugars

1) Preparation of solution of commercial rat small intestine acetone powder

Rat small intestine acetone powder, product of Sigma, is put into suspension with addition of physiological saline (0.9% NaCl). The suspension is urtrasonic treated (60 seconds, three times) and thereafter centrifuged (3000 r.p.m., 30 minutes) to obtain a supernatant serving as an enzyme solution. The protein content of the enzyme solution is determined by the Lowry method. The enzyme activity is adjusted to at least about 0.1 mg/mg protein/hour in terms of sucrose hydrolysis ability.

2) Digestion test with rat small intestine acetone powder

The sample to be used is the same extract as is obtained with use of 80% ethanol or water for the determination of total water-soluble sugar. The extract is concentrated and then diluted with 50 mM maleic acid-Na buffer (pH 6.0) to a sugar concentration of 1 to 4%. A 1.0 ml portion of the solution is admixed with 1.0 ml of the enzyme solution and is reacted therewith at 37° C. for 1 hour. The reaction mixture is heated in a boiling water bath for 10 minutes for inactivation and centrifuged (3000 r.p.m., 30 minutes) to obtain a supernatant. The reducing sugar content of the supernatant is determined by the Somogyi method, and the sugar alcohol content thereof by F-kit or gas chromatography. The sum of these contents is taken as the amount of enzyme-digested absorbable sugar. The contents determined are to include the reducing sugar and sugar alcohol which are originally present in the sample. The decomposition rate is the amount of digested absorbable sugar divided by the amount of total water-soluble sugar and multiplied by 100. As a control test, the same procedure as above is repeated for sucrose or maltose in the same amount as the total water-soluble sugar amount. When sucrose is used for the control test, the decomposition rate is to be at least 20%. The ratio of the decomposition rate obtained for sucrose or maltose to the decomposition rate obtained for the sugar determined is taken as the small intestine digestion absorption ratio; this ratio multiplied by the total water-soluble reducing sugar amount as the amount of total digested absorbable reducing sugar (B), and the amount of total digested absorbable sugar alcohol (C).

Which of sucrose and maltose is to be used as the control sugar is determined by the following method. Maltose in one-half the amount of the sugar determined is used as a substrate for a digestion test under the same condition as used for the digestion test with the rat small intestine acetone powder. If the amount of glucose then produced on digestion is up to 10 times the sum of the sugar and sugar alcohol resulting from the digestion test for the sugar determined, maltose is used as the control sugar. If the amount of glucose is larger than 10 times, sucrose is used.

3) Quantitive determination of protein

A 0.3 ml of 1N sodium hydroxide is added to 0.1 ml of sample (containing 20 to 100 μg of protein), and the mixture is allowed to stand for at least 15 minutes. 3 ml of solution A is then added to the mixture, followed by standing at room temperature for 10 minutes. Subsequently, 0.3 ml of solution B is added to the mixture, and 30 minutes thereafter, the mixture is checked for light absorbancy at 750 nm. Bovine serum albumin is used as a standard protein.

4-5 Equation for calculating physiological combustion heat

The amount of physiological combustion heat is the sum of amounts of effective energy due to digestion and absorption, and fermentation and absorption. Accordingly, the amount of physiological combustion heat is given by the following equation.

Amount of physiological combustion heat (kcal/g) =(starch A')×4+(amount of total digested absorbable reducing sugar (B))×4+(amount of total digested absorbable sugar alcohol (C))×2.8+((total water-soluble sugar A)-(amount of total digested absorbable reducing sugar (B)+amount of total digested absorbable sugar alcohol (C))×0.5.sup.(1) ×1.9.sup.(1)

5. Method-2 of Measuring Caloric Value

The effective caloric value of a sample is calculated as the sum of the caloric value resulting from digestion and absorption by the digestive system up to the upper digestive tract, and the caloric value resulting from intestinal fermentation after arrival of the sample at the large intestine.

Test 1: Measurement of caloric value resulting from digestion and absorption by the upper digestive tract up to the small intestine

The sample is dissolved in 45 mM (bis)Tris buffer (pH 6.0) containing 0.9 mM calcium chloride to obtain a 4.55% solution, to which 160 U/g of human saliva alpha-amylase (SIGMA Type IX-A) is added, followed by a reaction at 37° C. for 30 minutes. After deactivating the enzyme, the reaction mixture is desalted with an ion exchange resin and adjusted to a concentration of 1.1%. The aqueous solution (4 ml) is then added to 2 ml of 50 mM hydrochloric acid-potassium chloride buffer (pH 2.0), and the mixture is maintained at 37° C. for 100 minutes, followed by desalting with an ion exchange resin. To the desalted solution is added 45 mM (bis)Tris buffer (pH 6.0) containing 0.9 mM calcium chloride to adjust the solution to a concentration of 0.45%. To the solution is added 400U/g of swine pancreatic amylase (product of Boehringer Mannheim Yamanouchi Co., Ltd.), followed by a reaction at 37° C. for 6 hours. The enzyme is then deactivated, and the reaction mixture is thereafter desalted with an ion exchange resin, concentrated and lyophilized.

The powdery sample thus obtained is dissolved in 45 mM sodium maleate buffer (pH 6.6) to prepare a 0.45% solution, with which 86 U/g of rat small intestine mucous membrane enzyme (product of SIGMA) is reacted at 37° C. for 3 hours. The amount of glucose produced is measured by the pyranose oxidase method. The caloric value to be produced by digestion and absorption is calculated from the following equation. ##EQU1## Test 2: Determination of caloric value resulting from intestinal fermentation

The caloric value of the fraction reaching the large intestine was determined by the growth curve method using rats as described below.

                  TABLE 1                                                          ______________________________________                                         Component       Proportion (%)                                                 ______________________________________                                         Corn starch     42.7                                                           Casein          40.0                                                           Fiber           2.0                                                            Mineral mixture 10.0                                                           Vitamin mixture 0.8                                                            DL-methionine   0.3                                                            Choline bitartrate                                                                             0.2                                                            Vegetable oil   5.0                                                            ______________________________________                                    

Rats were preliminarily raised for 5 days to adapt them to the laboratory environment and to the basal diet shown in Table 1, then checked for body weight and health and divided into groups (10 rats in each group). The average initial body weight of all the test groups was 79.6 to 80.8 g. The body weight variations of the groups were in the range of 9 to 16 g. The caloric value of all the test components and basal diet was measured by a bomb calorimeter.

                  TABLE 2                                                          ______________________________________                                                Basic                     Total Caloric                                        diet     Glucose  Sample  amount                                                                               value                                   No.    (g)      (g)      (g)     (g)   (Kcal)                                  ______________________________________                                         1      5.4      --       --      5.4   22.7                                    2      5.4      0.5      --      5.9   24.7                                    3      5.4      1.0      --      6.4   26.7                                    4      5.4      2.0      --      7.4   30.7                                    5      5.4      4.0      --      9.4   38.7                                    6      5.4      --       0.5     5.9   24.7                                    7      5.4      --       1.0     6.4   26.7                                    8      5.4      --       2.0     7.4   30.7                                    9      5.4      --       4.0     9.4   38.7                                    ______________________________________                                    

After grouping, the rats were placed into individual steel cages and fed according to the experimental schedule listed in Table 2. The basal diet was given to all the rats in an amount of 5.4 g/rat/kg (22.7 kcal/rat/day). For the test groups, glucose or the above sample was added in an amount of 0.5, 1.0, 2.0 or 4.09 to the basal diet. The amount of glucose or sample added was about 2, 4, 8 or 16 kcal/rat/day in terms of caloric value. The amount of ingestion was measured daily, and the gain in the body weight was measured on the 0th, 5th, 10th and 15th days. The rats were checked generally every day by observation. Table 3 shows the results.

                  TABLE 3                                                          ______________________________________                                         Body weight          Consumed  Calories                                              Initial  Final   Gain    calories                                                                               needed for                              No.   g        g       g/14 day                                                                               KCal/day                                                                               1 g gain                                ______________________________________                                         1     79.2     74.4    -4.8    23.2    --                                      2     79.9     78.9    -1.0    24.8    --                                      3     79.4     85.5    6.1     26.2    0.017                                   4     79.5     89.9    10.4    27.6    0.027                                   5     79.6     96.2    16.6    28.9    0.041                                   6     80.3     79.2    -1.1    24.2    --                                      7     80.4     78.9    -1.5    26.9    --                                      8     78.8     81.4    2.6     28.3    0.007                                   9     79.9     86.9    7.0     29.6    0.017                                   ______________________________________                                    

With reference to Table 3, the caloric value determined by the animat experiment is:

    (0.007÷0.027×4+0.017÷0.041×4)÷2=1.35 kcal/g

From Test 1, the caloric value resulting from the digestion and absorption of the sample by the upper digestive tract is: ##EQU2##

Accordingly, the caloric value resulting from intestinal fermentation is:

    1.35-0.39=0.96 kcal/g

From this data, the caloric value produced by the intestinal fermentation of the dextrin is:

    0.96÷0.912 (proportion reaching the large intestine)=1.1 kcal/g=about 1 kcal/g

Thus, according to the methods of Test 1 and Test 2, the caloric value was calculated from the following equation. ##EQU3##

Experimental Example 1

Preparation of dextrin by extruder, structure of thereof and analysis of indigestible component

Using pressurized air, 22.5 liters of 1% solution of hydrochloric acid was sprayed onto 300 kg of commercial potato starch placed in a ribbon mixer while rotating the mixer, and the mixture was then passed through a disintegrator to obtain a uniform mixture, which was further treated in the ribbon mixer for 1 hour and pre-dried to a water content of about 8% by a flash dryer. A 270 kg portion of the mixture was continuously charged into a twin-screw extruder (Model TES 32FSS-20AW-V for foods, manufactured by Japan Steel Works, Ltd. and having screws rotatable in same or different directions on change-over, 32 mm in diameter and 20/l in length/diameter, drive motor 7.5 KW in output and rotatable at 400 r.p.m. max., aluminum cast heater, water cooling system with vent hole) and heat-treated at a temperature of 130° C., 140° C., 150° C., 160° C. or 170° C. under the following conditions to obtain five kinds of dextrins in a combined amount of about 220 kg. These samples will hereinafter be designated by sample Nos. 1, 2, 3, 4 and 5, respectively.

Speed of rotation: 150 r.p.m. (two screws driven in the same direction)

Inlet temperature: room temp. (about 20° C.)

Maximum temperature: 170° C. (temp. of product at outlet) Reaction time: 9 seconds

The indigestible component of each sample was quantitatively determined, and the sample was analyzed to determine the contents of glycosidic linkages thereof according to "Hakomori's methylation method". Detected by this procedure were a glucose residue at each non-reducing end, glucose residues having a 1→4 linkage, glucose residues having a 1→6 linkage, glucose residues having a 1→3 linkage, glucose residues each having both 1→4 linkage and 1→6 linkage, glucose residues each having both 1→3 linkage and 1→4 linkage, glucose residues each having both 1→2 linkage and 1→4 linkage, glucose residues each having both 1→2 linkage and 1→4 linkage, and glucose residues having other linkages. Table 4 shows the content of indigestible component and the values obtained by the analysis.

Incidentally, this method of quantitative determination involves errors which are usually about ±5% and which are inevitably at least ±2%.

                                      TABLE 4                                      __________________________________________________________________________              contents of linkages (%)                                                  Heating                                                                             Non-                       Content of                                 Sample                                                                             Temp.                                                                               reducing      1→4,                                                                       1→3,                                                                       1→2,                                                                           indigestible                               No. (°C.)                                                                        end  1→4                                                                        1→6                                                                        1→3                                                                        1→6                                                                        1→4                                                                        1→4                                                                        Others                                                                             component (%)                              __________________________________________________________________________     1   130  23.4 48.7                                                                               6.7                                                                              4.8                                                                               9.4                                                                               1.4                                                                               2.5                                                                               3.1 66.5                                       2   140  26.9 39.1                                                                               9.7                                                                              6.9                                                                               9.1                                                                               1.4                                                                               2.8                                                                               4.0 75.0                                       3   150  26.4 34.2                                                                              11.1                                                                              7.7                                                                               10.0                                                                              1.3                                                                               2.7                                                                               6.5 79.2                                       4   160  27.3 32.1                                                                              11.2                                                                              8.3                                                                               9.5                                                                               1.4                                                                               2.8                                                                               7.4 82.0                                       5   170  27.7 28.6                                                                              12.8                                                                              8.7                                                                               9.8                                                                               1.2                                                                               2.8                                                                               8.3 85.5                                       __________________________________________________________________________

Table 4 reveals the following. The content of indigestible component increases in proportion to the rise of temperature. Increases in proportion to the rise of temperature are also found in the amounts of glucose residues positioned at the non-reducing ends or having 1→6 glycosidic linkage, 1→3 glycosidic linkage, both 1→2 and 1→4 linkages, and in the amount of glucose residues having other linkages (listed as "Others" in Table 4, except the above residues, the residues having both 1→4 and 1→6 linkages and those having both 1→3 and 1→4 linkages and those having both 1→2 and 1→4 linkages).

The experiment demonstrates for the first time that only the amount of glucose residues having 1→4 linkage decreases in inverse proportion to the rise of temperature.

Next, the relation between the content of indigestible component and the linkages listed in Table 4 was investigated by multi-regression analysis capable of determining the correlation between a multiplicity of variables to obtain equations and multi-correlation coefficients. The multi-regression analysis was conducted using the amounts of glucose residues having various glycosidic linkages as predictor variables and the content of indigestible component as criterion variable.

First, the correlation between the content of indigestible component and the amounts of glucose residues having various glycosidic linkages was investigated. Table 5 shows the coefficients A0, A1, A2, A3, A4, A5, A6, A7 and A8 of the equation and correlation coefficients obtained.

    Y=A0+An·Xn

Wherein

Y: content of indigestible component (calculated value, %)

X1: amount (%) of glucose residues at the non-reducing end

X2: amount (%) of glucose residues having a 1→4 glycosidic linkage

X3: amount (%) of glucose residues having a 1→6 glycosidic linkage

X4: amount (%) of glucose residues having a 1→3 glycosidic linkage

X5: amount (%) of glucose residues having both 1→4 and 1→6 glycosidic linkages

X6: amount (%) of glucose residues having both 1→3 and 1→4 glycosidic linkages

X7: amount (%) of glucose residues having both 1→2 and 1→4 glycosidic linkages

X8: amount (%) of glucose residues having other glycosidic linkages

                                      TABLE 5                                      __________________________________________________________________________     Coefficient                          correlation                               No.                                                                               A0   A1 A2  A3 A4 A5  A6   A7  A8 coefficient                               __________________________________________________________________________     1  -26.2                                                                               3.492                                                                             --  -- -- --  --   --  -- 0.922                                     2  111.9                                                                               -- -0.938                                                                             -- -- --  --   --  -- 0.998                                     3  45.0 -- --  3.164                                                                             -- --  --   --  -- 0.991                                     4  43.3 -- --  -- 4.712                                                                             --  --   --  -- 0.994                                     5  -25.5                                                                               -- --  -- -- 11.788                                                                             --   --  -- 0.517                                     6  150.0                                                                               -- --  -- -- --  -54.000                                                                             --  -- 0.660                                     7  -49.8                                                                               -- --  -- -- --  --   46.851                                                                             -- 0.835                                     8  59.1 -- --  -- -- --  --   --  3.157                                                                             0.960                                     __________________________________________________________________________

Consequently, of the eight kinds of glycosidic linkages, X5 (amount of glucose residues having both 1→4 and 1→6 glycosidic linkages), X6 (amount of glucose residues having both 1→3 and 1→4 glycosidic linkages) and X7 (amount of glucose residues having both 1→2 and 1→4 glycosidic linkages) were found to be very low in correlation efficient (0.517, 0.660 and 0.835 respectively for No.5, No.6 and No.7 in Table 5), this indicating that the amounts of these glucose residues have no correlation with the content of indigestible component. Accordingly, multi-regression analysis was conducted to determine the relation between the content of indigestible component and the amounts of glucose residues having the following five types of glycosidic linkages other than the above three types of glycosidic linkages. For the 31 equations which are at least 0.9 in correlation coefficient and which are included in the equations obtained, Tables 6-1 to 6-2 show the following coefficients.

    Y:A0+A1·X1+A2·X2+A3·X3+A4·X4+A5.multidot.X5+A6·X6

wherein

Y: content (%) of indigestible component (calculated value)

X1: amount (%) of glucose residues at the non-reducing end

X2: amount (%) of glucose residues having a 1÷4 glycosidic linkage

X3: amount (%) of glucose residues having a 1→6 glycosidic linkage

X4: amount (%) of glucose residues having a 1→3 glycosidic linkage

X5: amount (%) of glucose residues having glycosidic linkages other than the above residues, glycosidic residues having both 1→4 and 1→6 glycosidic linkages, glycosidic residues having both 1→3 and 1→4 glycosidic linkages and glycosidic residues having both 1→2 and 1→4 glycosidic linkages

                                      TABLE 6-1                                    __________________________________________________________________________                                      Multi-                                        Coefficient                      correlation                                   No.                                                                               A0   A1   A2   A3   A4   A5   coefficient                                   __________________________________________________________________________      1 -26.2                                                                               3.492                                                                               --   --   --   --   0.922                                          2 111.9                                                                               --   -0.938                                                                              --   --   --   0.998                                          3 45.0 --   --   3.164                                                                               --   --   0.991                                          4 43.3 --   --   --   4.712                                                                               --   0.994                                          5 59.1 --   --   --   --   3.157                                                                               0.960                                          6 116.3                                                                               -0.130                                                                              -0.965                                                                              --   --   --   0.998                                          7 43.0 0.105                                                                               --   3.091                                                                               --   --   0.991                                          8 57.9 -0.779                                                                              --   --   5.531                                                                               --   0.995                                          9 16.0 1.891                                                                               --   --   --   2.021                                                                               0.999                                         10 123.4                                                                               --   -1.099                                                                              -0.548                                                                              --   --   0.998                                         11 124.5                                                                               --   -1.110                                                                              --   -0.868                                                                              --   0.998                                         12 106.8                                                                               --   -0.849                                                                              --   --   0.326                                                                               0.999                                         13 43.8 --   --   1.295                                                                               2.815                                                                               --   0.996                                         14 48.1 --   --   2.356                                                                               --   0.892                                                                               0.996                                         15 46.5 --   --   --   3.632                                                                               0.800                                                                               0.997                                         16 126.5                                                                               -0.109                                                                              -1.112                                                                              -0.517                                                                              --   --   0.998                                         17 124.4                                                                               -0.008                                                                              -1.106                                                                              --   -0.840                                                                              --   0.998                                         18 58.5 1.022                                                                               -0.404                                                                              --   --   1.196                                                                               0.999                                         19 56.3 -0.671                                                                              --   1.162                                                                               3.715                                                                               --   0.997                                         20 25.0 1.327                                                                               --   0.830                                                                               --   1.562                                                                               1.000                                         21 12.9 2.087                                                                               --   --   -0.393                                                                              2.158                                                                               0.999                                         __________________________________________________________________________

                                      TABLE 6-2                                    __________________________________________________________________________                                      Multi-                                        Coefficient                      correlation                                   No.                                                                               A0   A1   A2   A3   A4   A5   coefficient                                   __________________________________________________________________________     22 164.6                                                                               --   -1.663                                                                              -1.128                                                                              -1.998                                                                              --   0.999                                         23 111.0                                                                               --   -0.910                                                                              -0.182                                                                              --   0.299                                                                               0.999                                         24 105.9                                                                               --   -0.838                                                                              --   0.051                                                                               0.332                                                                               0.999                                         25 46.5 --   --   1.026                                                                               2.249                                                                               0.711                                                                               0.999                                         26 289.2                                                                               1.483                                                                               -3.759                                                                              -3.889                                                                              -10.051                                                                             --   1.000                                         27 15.4 1.933                                                                               --   0.930                                                                               -1.350                                                                              1.977                                                                               1.000                                         28 68.3 1.844                                                                               -0.726                                                                              --   -3.026                                                                              1.594                                                                               1.000                                         29 -27.4                                                                               2.008                                                                               0.587                                                                               1.683                                                                               --   2.289                                                                               1.000                                         30 1390.1                                                                              --   -18.949                                                                             -23.381                                                                             -45.838                                                                             -7.774                                                                              1.000                                         31 59.41                                                                               1.859                                                                               -0.604                                                                              0.156                                                                               -2.744                                                                              1.658                                                                               1.000                                         __________________________________________________________________________

In the multi-correlation analysis using the five predictor variables, combinations of one to five predictor variables are 31 in total number. These 31 combinations are all at least 0.922 in multi-correlation coefficient. This indicates that there is a very close correlation between the amount of glucose residues having glycosidic linkages and the content of indigestible component.

Comparative Example 1

Preparation of dextrin by conventional process, structure of the dextrin and analysis of indigestible component

A 5 kg portion of the remaining mixture of Experimental Example 1 was placed into a dryer and heated to 150° C. Five kinds of samples, each in an amount of 800° C., were collected from the heated mixture respectively 15 minutes, 30 minutes, 60 minutes, 120 minutes and 180 minutes after the start of heating.

The samples were analyzed similarly to determine the contents of glycosidic linkages thereof according to "Hakomori's methylation method". Detected by this procedure were glucose residues at the non-reducing ends, glucose residues having a 1→4 linkage, glucose residues having a 1→6 linkage, glucose residues each having both 1→4 linkage and 1→6 linkage, and glucose residues having 1→3 linkage and glucose residues each having both 1→4 linkage and 1→6 linkage, glucose residues each having both 1→3 linkage and 1→4 linkage, glucose residues each having both 1→2 linkage and 1→4 linkage, and glucose residues having other linkages. Table 7 shows the detected values and the content of indigestible component.

                                      TABLE 7                                      __________________________________________________________________________     contents of linkages (%)                                                       Heating                                                                             Non-                       Content of                                     Time reducing      1→4,                                                                       1→3,                                                                       1→2,                                                                           indigestible                                   (min)                                                                               end  1→4                                                                        1→6                                                                        1→3                                                                        1→6                                                                        1→4                                                                        1→4                                                                        Others                                                                             component (%)                                  __________________________________________________________________________     15   10.6 78.7                                                                              1.7                                                                               -- 6.8                                                                               1.0                                                                               1.2                                                                               --  24.4                                           30   14.6 70.7                                                                              2.7                                                                               -- 9.0                                                                               1.3                                                                               1.7                                                                               --  34.3                                           60   17.4 62.7                                                                              4.3                                                                               -- 12.2                                                                              1.2                                                                               2.2                                                                               --  43.5                                           120  14.7 67.4                                                                              5.1                                                                               -- 9.4                                                                               1.0                                                                               2.4                                                                               --  56.8                                           180  13.2 50.3                                                                              4.9                                                                               1.5                                                                               11.1                                                                              1.3                                                                               2.3                                                                               15.4                                                                               60.9                                           __________________________________________________________________________

Table 7 shows the following. The content of indigestible component increases in proportion to the increase in heating time. The amount of glucose residues having 1→4 linkage decreases in almost inverse proportion to the increase in heating time, while the amount of glucose residues having 1→6 linkage increases in almost proportion to the increase in heating time, thus exhibiting a tendency similar to that of Table 4. However, the amount of glucose residues at the non-reducing ends and glucose residues having other linkages have no correlation with the heating condition. In this respect, the result of Table 7 greatly differs from that of Table 4. This has been revealed by the present experiment for the first time.

Experimental Example 2

About 220 kg of a dextrin was prepared in the same manner as in Experimental Example 1 with the exception of adding 17.5 liters of 1% hydrochloric acid to 300 kg of commercial potato starch, treating the starch in the same manner as in Experimental Example 1 and thereafter heating the starch to 180° C. The product was analyzed in the same manner as in Experimental Example 1.

Experimental Example 3

About 220 kg of a dextrin was prepared in the same manner as in Experimental Example 1 with the exception of adding 17.5 liters of 1% hydrochloric acid to 300 kg of commercial potato starch, treating the starch in the same manner as in Experimental Example 1 and thereafter heating the starch to 160° C. The product was analyzed in the same manner as in Experimental Example 1. Table 8 shows the results of Experimental Example 2 and 3.

                                      TABLE 8                                      __________________________________________________________________________     contents of linkages (%)                                                            Non-                       Content of                                     Exp. reducing      1→4,                                                                       1→3,                                                                       1→2,                                                                           indigestible                                   Example                                                                             end  1→4                                                                        1→6                                                                        1→3                                                                        1→6                                                                        1→4                                                                        1→4                                                                        Others                                                                             component (%)                                  __________________________________________________________________________     2    23.7 47.8                                                                               7.3                                                                              4.9                                                                               9.1                                                                               1.2                                                                               2.4                                                                               3.6 67.7                                           3    27.5 29.0                                                                              12.9                                                                              8.4                                                                               9.8                                                                               1.5                                                                               2.9                                                                               8.0 85.0                                           __________________________________________________________________________

The values listed in Table 8 were substituted in the equations 1 to 30 given in Table 6 to calculate content values of indigestible component, Y. Table 9 shows a summary of results as converted to values in percentage.

                                      TABLE 9                                      __________________________________________________________________________                                  Exp. Example                                      Item                         2    3                                            __________________________________________________________________________     Maximum variation range + (%)                                                                               4.1  7.9                                          Maximum variation range - (%)                                                                               -9.8 -3.3                                         Average variation range + (%)                                                                               1.2  1.8                                          Average variation range - (%)                                                                               -1.4 -1.0                                         Number of cases with variation range of over +15.1%                                                         0    0                                            Number of cases with variation range of +10.1% to +15%                                                      0    0                                            Number of cases with variation range of 0.1% to +10%                                                        10   7                                            Number of cases with variation range of 0%                                                                  1    3                                            Number of cases with variation range of -0.1% to -10%                                                       19   20                                           Number of cases with variation range of -10.1% to -15%                                                      0    0                                            Number of cases with variation range of over -15.1%                                                         0    0                                            Number of cases with variation range within ±5%                                                          29   29                                           Number of cases with variation range within ±2%                                                          28   26                                           __________________________________________________________________________

With reference to Table 9, Experimental Example 2 by extruder, all the 30 cases were within the range of ±10% in the variation of the calculated value Y from the actual measurement. The variation was within ±5% in 29 cases and within ±2% in 28 cases.

In Experimental Example 3 all the 30 cases were within the range of ±10% in the variation of the calculated value Y from the actual measurement. The variation was within ±5% in 29 cases and within ±2% in 26 cases. These results indicate that the equation in Table 6 are very high in correlation between the glycosidic linkages of the dextrin and the content of indigestible component thereof.

Similarly, the values listed in Table 7 were substituted in the equations 1 to 31 in Table 6 to calculate content values of indigestible component, Y. Table 10 shows a summary of results as converted to values in percentage.

                                      TABLE 10                                     __________________________________________________________________________                     Heating time (min)                                             Item            15    30    60  120  180                                       __________________________________________________________________________     Maximum variation range + (%)                                                                  142.2 72.3  133.2                                                                              7.6  119.9                                     Maximum variation range - (%)                                                                  -677.6                                                                               -137.1                                                                               -2.5                                                                               6.2  -57.6                                     Average variation range + (%)                                                                  70.2  36.2  26.1                                                                               5.9  22.6                                      Average variation range - (%)                                                                  -267.9                                                                               -72.8 -1.5                                                                               -20.8                                                                               -14.3                                     Number of cases with variation                                                                 28    28    23  0    13                                        range of over +15.1%                                                           Number of cases with variation                                                                 0     0     4   0    5                                         range of +10.1% to +15%                                                        Number of cases with variation                                                                 0     1     2   4    6                                         range of 0.1% to +10%                                                          Number of cases with variation                                                                 0     0     0   0    0                                         range of 0%                                                                    Number of cases with variation                                                                 0     1     2   2    4                                         range of -0.1% to -10%                                                         Number of cases with variation                                                                 0     0     0   11   1                                         range of -10.1% to -15%                                                        Number of cases with variation                                                                 3     1     0   14   2                                         range of over -15.1%                                                           Number of cases with variation                                                                 0     5     3   1    3                                         range within ±5%                                                            Number of cases with variation                                                                 0     3     2   0    1                                         range within ±2%                                                            __________________________________________________________________________

With reference to Table 10 showing the results achieved by the samples of dextrin prepared by the conventional process, the samples were extremely great in variation range and had little or no correlation with the equations of Table 6. This indicates that the difference in heating process resulted in a great difference in the structure of product.

Comparative Example 2

About 240 kg of a dextrin was prepared in the same manner as in Experimental Example 1 with the exception of adding 22.5 liters of 1% hydrochloric acid to 300 kg of commercial corn starch, treating the starch in the same manner as in Experimental Example 1 and thereafter heating the starch to 140° C. The product was analyzed in the same manner as in Experimental Example 1.

Comparative Example 3

About 230 kg of a dextrin was prepared in the same manner as in Experimental Example 1 with the exception of adding 22.5 liters of 1% hydrochloric acid to 300 kg of commercial sweet potato starch, treating the starch in the same manner as in Experimental Example 1 and thereafter heating the starch to 140° C. The product was analyzed in the same manner as in Experimental Example 1. Table 11 shows the results of analysis obtained in Comparative Examples 2 and 3.

                                      TABLE 11                                     __________________________________________________________________________     contents of linkages (%)                                                            Non-                       Content of                                     Comp.                                                                               reducing      1→4,                                                                       1→3,                                                                       1→2,                                                                           indigestible                                   Example                                                                             end  1→4                                                                        1→6                                                                        1→3                                                                        1→6                                                                        1→4                                                                        1→4                                                                        Others                                                                             component (%)                                  __________________________________________________________________________     2    28.6 40.3                                                                              10.8                                                                              5.3                                                                                8.7                                                                              1.0                                                                               2.2                                                                               3.1 69.4                                           3    18.0 55.4                                                                               4.6                                                                              2.5                                                                               11.2                                                                              1.7                                                                               3.3                                                                               3.3 50.0                                           __________________________________________________________________________

The results obtained by analyzing the products of the above two comparative examples were substituted in the equation 31 wherein all the five variables were used to calculate the content values of indigestible component. Table 12 shows the calculated values in comparison with the actual measurements.

                  TABLE 12                                                         ______________________________________                                                Indigestible component                                                                                Range of                                         Comp.    Measured   Calculated                                                                               variation from                                   Example  (%)        (%)       measurement (%)                                  ______________________________________                                         2        69.4       80.5      +16.0                                            3        50.0       58.7      +17.4                                            ______________________________________                                    

Table 12 shows that even if heat-treated by the same process, different material starches afford products which are greatly different in structure.

Experimental Example 4

Eleven samples of the dextrins prepared in Experimental Examples 1, 2, 3 and Comparative Example 1 were checked for the degree of coloration by measuring the whiteness of the samples relative to the whiteness of magnesium oxide taken as 100%, using photoelectric whiteness meter (product of Kett Co.) and a blue filter. Table 13 shows the results.

                  TABLE 13                                                         ______________________________________                                         Sample                   Whiteness (%)                                         ______________________________________                                         Exp. Ex. 1 Heating Temp.                                                                              130° C.                                                                           29.4                                                                 140° C.                                                                           28.0                                                                 150° C.                                                                           24.9                                                                 160° C.                                                                           22.4                                                                 170° C.                                                                           20.7                                          Exp. Ex. 2 Heating Temp.                                                                              180° C.                                                                           21.0                                          Exp. Ex. 3 Heating Temp.                                                                              160° C.                                                                           23.6                                                                 15 min    23.6                                          Comp. Ex. 1                                                                               Heating time                                                                               30 min    19.5                                          Heating                60 min    17.8                                          Temp. 150° C.   120 min   16.2                                                                 180 min   15.4                                          ______________________________________                                    

The whiteness decreased generally in inverse proportion to the heating temperature or heating time. However, the whiteness of comparative example 1 is such lower that of the products of present invention. This reveals that the conventional products were not practically useful.

Experimental Example 5

Sample Nos. 1, 2, 3, 4 and 5 were checked for the content of dietary fiber and caloric values as determined by the foregoing two measuring methods. Table 14 shows the results along with the content indigestible component.

                  TABLE 14                                                         ______________________________________                                                Indigestible                                                                           Component   Caloric value                                       Sample   content   of dietary  1     2                                         No.      (%)       fiber (%)   Kcal/g                                                                               Kcal/g                                    ______________________________________                                         1        66.5      26.2        2.42  2.01                                      2        75.0      32.5        2.22  1.75                                      3        79.2      36.2        2.12  1.62                                      4        82.0      39.3        2.05  1.54                                      5        85.5      41.7        1.97  1.44                                      ______________________________________                                    

The values given in Table 14 appear to indicate that the dietary fiber content is in proportional relation with the content of indigestible component and is in inversely proportional relation with the caloric values. Accordingly, the correlation of the content of indigestible component with the dietary fiber content and with the caloric values was determined by the least square method to obtain Equation 32 as to the dietary fiber content, Equation 33 as to the caloric value 1 and Equation 34 as to the caloric value 2.

Equation 32:

    Y.sub.1 =22.43-0.451·I+1.37·10.sup.-3 ·I.sup.2 +1.537·10.sup.-4 ·I.sup.3 -8.99·10.sup.-7 ·I.sup.4

Equation 33:

    Y.sub.2 =4.00=0.0237·I

Equation 34:

    Y.sub.3 =4.01-0.0301·I

wherein

Y1: dietay fiber content (calculated value, %)

Y2: caloric value 1 (calculated value, kcal/g)

Y3: caloric value 2 (calculated value, kcal/g)

I: content of indigestible component (analyzed value, %)

Next, the content of indigestible component was substituted in these three equations. Tables 15, 16 and 17 show the calculated values obtained in comparison with measured values.

                  TABLE 15                                                         ______________________________________                                                                Difference between                                             Content of dietary                                                                             calculated value and                                    Sample fiber (%)       measurement (%)                                         No.    Measured  Calculated                                                                               Difference                                                                             Variation ratio                             ______________________________________                                         1      26.2      26.1      -0.1    -0.4                                        2      32.5      32.7      0.2     0.6                                         3      36.2      36.3      0.1     0.3                                         4      39.3      38.8      -0.5    -1.3                                        5      41.7      41.9      0.2     0.5                                         ______________________________________                                    

                  TABLE 16                                                         ______________________________________                                                                Difference between                                             Caloric value 1 calculated value and                                    Sample (Kcal/g)        measurement (%)                                         No.    Measured  Calculated                                                                               Difference                                                                             Variation ratio                             ______________________________________                                         1      2.42      2.42      0.00    0.0                                         2      2.22      2.22      0.00    0.0                                         3      2.12      2.12      0.00    0.0                                         4      2.05      2.05      0.00    0.0                                         5      1.97      1.97      0.00    0.0                                         ______________________________________                                    

                  TABLE 17                                                         ______________________________________                                                                Difference between                                             Caloric value 2 calculated value and                                    Sample (Kcal/g)        measurement (%)                                         No.    Measured  Calculated                                                                               Difference                                                                             Variation ratio                             ______________________________________                                         1      2.01      2.01      0.00    0.0                                         2      1.75      1.75      0.00    0.0                                         3      1.62      1.63      0.01    0.6                                         4      1.54      1.54      0.00    0.0                                         5      1.44      1.44      0.00    0.0                                         ______________________________________                                    

The calculated values given in Tables 15 to 17 are well in match with the respective measured values. This demonstrates a close relation of the content of indigestible content with the dietary fiber content as well as with the caloric values.

Next, investigations were made to determine the physiological activities of the indigestible dextrin of the invention using commercial white dextrin and samples Nos. 3 and 5 of Experimental Example 1. These three samples will hereinafter be referred to as "samples A, B and C," respectively.

Experimental Example 6

Animal experiment

Male rats of Sprague-Dawley strain (6 rats/group) initially weighing about 50 g were accommodated in individual cages placed in a small animal breeding chamber controlled to 23±2° C., preliminarily raised with a commercial synthetic diet for 1 week, and thereafter fed for 7 days with a basal diet, or the basal diet containing 5% of the sample A, B or C added thereto, or the basal diet containing 5% cellulose (Avicel, product of Sanyo-Kokusaku Pulp Co., Ltd.) with free access to water and the diet. The intake of diet and changes in body weight were recorded daily. On the seventh day, carmine (pigment) was given as admixed with the diet, and the time taken for the carmine to appear in feces was measured as transit time. The animals were thereafter sacrificed with blood taken, and the cecum was removed and checked for the weight thereof, pH of the contents of the cecum and the amount of burytic acid therein. Table 18 shows the average values of results obtained.

                                      TABLE 18                                     __________________________________________________________________________                 Weight of                                                                            Contents of                                                                          Amount of butyric                                                                        Excretion time                                           cecum (g)                                                                            cecum (pH)                                                                           acid (mg/cecum)                                                                          (hr)                                         __________________________________________________________________________     Basal diet  1.2   8.0    4.0      13.2                                         Basal diet + Sample A                                                                      4.1   6.3   16.6      9.4                                          Basal diet + Sample B                                                                      4.6   5.9   23.2      8.2                                          Basal diet + Sample C                                                                      5.5   5.8   27.3      7.7                                          Basal diet + cellulose                                                                     2.5   7.6    4.3      8.2                                          __________________________________________________________________________

The results listed in Table 18 reveal that the sample A, B or C reached the large intestine while remaining indigested, metabolized to organic acids under the action of enterobacteria and resulted in a lower pH within the intestine. While the ingestion of any of the samples A, B and C shortened the transit time, comparison with the group receiving cellulose, which is effective for improved defecation, indicated that the samples B and C were effective. Accordingly, the sample B was further used for clinical tests to substantiate its effect.

Experimental Example 7

Clinical test

The sample B was given at a daily dose 10 g to ten males in good health during a test period of 2 weeks. During the first and second weeks of the test period, they are given the same meals in same quantities, and the sample was administered after breakfast on Monday through Friday. Feces were collected on every defecation and checked for wet weight, dry weight, water content and frequency of defecation. Table 19 shows the results obtained. The values listed are mean values, and the mark * indicates a significance level of 5% relative to the non-ingestion period, hence a significant difference.

                  TABLE 19                                                         ______________________________________                                                         Non-ingestion                                                                               Ingestion                                         Test period     period       period                                            ______________________________________                                         Wet weight      542 g        788 g*                                            of feces                                                                       Dry weight      120 g        159 g*                                            of feces                                                                       Amount of water 422 g        629 g*                                            in feces                                                                       Water content    77.8%        79.8%                                            of feces                                                                       Frequency of     4.4 times    6.0 times*                                       excretion                                                                      ______________________________________                                    

The results of Table 19 reveal that the sample has an effect to increase the overall amount of feces.

Experimental Example 8

Clinical test

The sample B was checked for a constipation alleviating effect. The sample was given to 25 volunteers having a tendency toward constipation at a predetermined dose for at least 5 days. Changes resulting from the administration of the sample in defecation were checked with a questionnaire. Scores are assigned to the checked items on the questionnaire according to the following criteria to substantiate the effect through a statistical procedure.

(1) Frequency of excretion

At least once/day: score 4

Once/day: score 3

Once/two days: score 2

Once/three days : score 1

(2) Amount of excretion

Large: score 4

Usual: score 3

Small: score 2

None: score 1

(3) State of feces

Bananalike, pasty: score 2

Hard: score 1

(4) Feeling after defecation

Complete discharge: score 2

Incomplete discharge: score 1

Table 20 shows the results. The mark * listed indicates a significance level of 5% relative to "before administration," hence a significant difference.

                  TABLE 20                                                         ______________________________________                                                          Amount administered                                                            5 g   10 g                                                    ______________________________________                                         Before administration                                                                             8.52    8.55                                                After administration                                                                              11.20*  12.50*                                              ______________________________________                                    

With reference to Table 20, the sample B, when administered at a dose of at least 5 g, resulted in increased scores and was found effective for alleviating constipation.

Experimental Example 9

Animal test

Rats were used for a nutritional experiment to check the samples A, B and C for a serum lipid lowering effect.

Male rats of Sprague-Dawley strain initially weighing about 50 g (3-week-old, provided by CLEA Japan Co.) were preliminarily raised for two weeks on a high-sucrose diet (basal diet) shown in Table 21, and thereafter raised and divided into five groups (10 rats in each group) for 9 weeks, during which the basal diet was given to the first group (control group), and a test diet comprising 95% of the basal diet and 5% of the sample A, B or C admixed therewith was given the second group (sample A group), third group (sample B group) and fourth group (sample C group), with free access to the diet and water.

                  TABLE 21                                                         ______________________________________                                         Material           Weight parts                                                ______________________________________                                         Casein             25                                                          Corn oil           5                                                           Salt (MM-2) mixture                                                                               4                                                           Vitamin (Harper) mixture                                                                          1                                                           Choline chloride   0.2                                                         Vitamin E          0.05                                                        Sucrose            64.75                                                       ______________________________________                                    

In the 9th week, the rats were fasted for 4 hours, blood was then taken, and the serum total cholesterol value and neutral fat value thereof were determined by a kit for enzyme method (product of Wako Jun-yaku Co., Ltd.). Table 22 shows the results.

                  TABLE 22                                                         ______________________________________                                                    Group                                                               Item         1st     2nd       3rd   4th                                       ______________________________________                                         Weight gain  298     295       292   288                                       (g/9 weeks)                                                                    Diet efficiency                                                                             0.25    0.25      0.25  0.25                                      Serum total  121     88        67    65                                        cholesterol                                                                    Serum neutral                                                                               275     199       133   127                                       fat                                                                            ______________________________________                                    

The results achieved by the test groups are expressed in mean values. The diet efficiency was calculated from Equation 35.

Equation 35:

    Diet efficiency=weight gain÷diet intake

As seen from Table 22, there was no difference between the three sample groups in weight gain and diet efficiency. However, the sample A, B and C groups were apparently lower in serum total cholesterol value and neutral fat value than the control group. The samples B and C were found to be remarkably effective. Accordingly, sample B was further tested clinically.

Experimental Example 10

Clinical test

Sample B (10 g) was dissolved in 100 ml of water, and the solution was orally administered to 10 persons three times a day before every meal for four weeks, during which they observed usual eating habits and were allowed to perform routine work. The persons participating in the test were 34 to 61 years old (53.3 on the average age), 161 to 173 cm tall (166.8 cm on the average) and weighed 54 to 82 kg (65.9 kg on the average). Table 23 shows the results obtained as expressed in the unit of mg/dl.

                  TABLE 23                                                         ______________________________________                                                   Normal     Before     After                                          Item      value      administration                                                                            administration                                 ______________________________________                                         Total     120˜250                                                                             235        174                                            cholesterol                                                                    HDL-      40˜65                                                                                45         49                                            cholesterol                                                                    Neutral fat                                                                               67˜172                                                                             255        170                                            ______________________________________                                    

Table 23 reveals that the administration of the sample B altered the serum total cholesterol value toward the normal value (120˜250 mg/dl). Those who were higher than the normal in this value exhibited a reduction. As similar result was observed also with respect to the neutral fat value. These results substantiate that the sample B has a remarkable effect in improving serum lipid metabolism.

Experimental Example 11

Insulin

An experiment conducted with 36 rats revealed that the blood sugar value of 82.0 mg/dl on average and the insulin secretion of 16.5 μU/ml on average, when the rats were hungry, increased to the highest levels of 165 mg/dl and 52.2 μU/dl on average, respectively, 30 minutes after sugar was orally given to the rats in an amount of 1.5 g/kg body weight, and lowered to the respective normal values 120 minutes thereafter. However, addition of the sample B to the sugar in an amount of 0.15 to 1.5 g (in a proportion of 1/10 to 1/1 to the amount of sugar) resulted in smaller increases 30 minutes after administration; the average blood sugar value and the average value of insulin secretion thereby increased and were 143 mg/dl and 33.3 μU/ml, respectively, when the proportion was 1/10 and 145 mg/dl and 35.0 μU/ml, respectively, when the proportion was 1/1. This indicates that the indigestible dextrin significantly suppresses the rise of blood sugar value and insulin secretion due to sugar.

Incidentally, when 0.15 g of sample A was similarly added to the sugar, the blood sugar value increased to 163 mg/dl on average 30 minutes later, i.e., to the same level as when sugar only was orally administered.

Summary of Experimental Data as Analyzed

To sum up the results obtained by analyzing the foregoing experimental data, the dextrin of the invention prepared by heating starch in an extruder greatly differs from the dextrin of the prior art with respect to the following in the case where the content of indigestible component is at lest 67%.

(1) The content of indigestible component is 85.5% at the maximum.

(2) The content of glucose residues having 1→4 glycosidic linkage is about 29% to about 49%, whereas the corresponding value of the prior art is at least about 60%.

(3) The content of glucose residues having 1→6 glycosidic linkage is about 7 to about 13% maximum, whereas the corresponding value of the prior art is only 4%.

(4) The content of glucose residues having 1→3 glycosidic linkage is about 5 to 9% in contrast to only traces of these residues found in the conventional product.

(5) The content of glucose residues having other glycosidic linkages is about 3 to about 8%, whereas the corresponding value of the prior art is at least about 20%.

(6) The contents of glucose residues having various glycosidic linkages other than those having the above linkages, having both 1→4 and 1→6 glycosidic linkages, having both 1→3 and 1→4 glycosidic linkages, and having both 1→2 and 1→4 glycosidic linkages are in close correlation with the content of indigestible component.

(7) Among the 31 equations, the equation 31 including all the five predictor variables represents the closest relationship between the whole of glycosidic linkages and the content of indigestible component involved in the present dextrin which is prepared by adding hydrochloric acid to potato starch and then heating the starch by an extruder. The content value of indigestible component obtained by similarly heating a starch other than potato starch, i.e., corn starch or sweet potato starch, with addition of an acid using an extruder, analyzing the heat-treated starch to determine the contents of glycosidic linkages thereof and substituting the content values in the equation 31 is greatly different from actual measurement. Apparently, therefore, the equation is applicable specifically to potato starch only.

(8) As the heating temperature rises, the product contains a larger amount of colored substance, resulting in the whiteness level lowering to about 20% which is considered to be the lower limit for use of the product as a food material. Thus, the heating temperature is limited for the use of the product.

The above experimental results indicate that the dextrin of the present invention is a novel substance which has a higher content of indigestible component than the dextrin obtained by the conventional heat treatment process and which distinctly differs from the conventional product in structure.

(9) It has been further found that the content of indigestible component has a close correlation with the dietary fiber content and also with the caloric value.

(10) Furthermore, the indigestible dextrin, when ingested, is found effective for improving the internal environment of the intestine and eliminating constipation and diarrhea by giving a lower pH to the interior of the intestine and increasing the amounts of short-chain fatty acids having an intestine conditioning effect.

(11) The dextrin further acts to diminish cholesterol and neutral fats among other serum lipids, consequently preventing arterial sclerosis and hypertension.

(12) The dextrin further has an effect to reduce the rise of blood sugar and insulin secretion after meals.

(13) Because of these effects, the indigestible dextrin of the present invention is very useful as a material for alimentotherapy to accomplish the above purposes.

Next, as to the heating condition for the extruder, it is desirable to use a high temperature to give an increased content of indigestible component as is apparent from Table 1. To obtain a product with an indigestible content of at least 66%, the treatment is conducted at a temperature of at least about 130° C., preferably at least 140° C. The product can then be 75% or higher in content. However, the treatment may be conducted at a relatively low temperature when a large-sized extruder is employed because the reaction time is then longer owing to the structure of the apparatus.

Although the progress of the reaction is controllable by using an increased amount of acid, but presence of a large excess of acid causes corrosion or abrasion to the extruder. Accordingly, it is suitable to use up to 3,000 ppm, more preferably about 1,000 ppm, of acid based on the starch material.

The product as heat-treated by the extruder contains hydrochloric acid and therefore needs to be neutralized and thereafter refined, for example, by decoloration with activated carbon, filtration and desalting with ion exchange resin when to be used for purposes other than feeds. However, if the material starch is heated in the extruder at high temperatures over 180° C., an increased amount of colored substance will result to impair the quality of the product in spite of neutralization and purification. The product is accordingly undesirable for use in foods.

Further, the product to be refined can be hydrolyzed with alpha-amylase and thereby given a reduced viscosity. This also permits more efficient refining. The refined product can be given a higher content of indigestible component by being subjected to continuous chromatography with use of an ion exchange resin of the alkali metal or alkaline earth metal type to separate off the digestible component.

EXAMPLE

Examples of the invention are given below.

Example 1

Commercial potato starch (500 kg) was placed into a ribbon mixer, and 50 liters of 1% hydrochloric acid solution was sprayed onto the starch by pressurized air while rotating the mixer. The mixture then passed through a disintegrator to obtain a uniform mixture, which was further treated in the ribbon mixer for 1 hour. The mixture was pre-dried to a water content of about 6% by a flash dryer, subsequently continuously charged into a twin-screw extruder (Model TEX-52FSS-20AW-V for foods, manufactured by Japan Steel Works, Ltd. and having screws rotatable in same or different directions on change-over, 52 mm in diameter and 20/1 in length/diameter, drive motor 7.5 KW in output and rotatable at 400 r.p.m. max., aluminum cast heater, water cooling system with vent hole) and heat-treated under the following conditions to obtain about 360 kg of indigestible dextrin with moisture content of 2.9%.

Speed of rotation: 150 r.p.m., two screws rotated in the same direction

Inlet temperature: room temp. (about 20° C.)

Heating temperature: 150% (temp. of product at outlet)

Reaction time: 9 seconds

Example 2

Commercial potato starch (500 kg) was placed into a ribbon mixer, and 35 liters of 1% hydrochloric acid solution was sprayed onto the starch by pressurized air while rotating the mixer. The mixture then passed through a disintegrator to obtain a uniform mixture, which was further treated in the ribbon mixer for 1 hour. The mixture was pre-dried to a water content of about 6% by a flash drier, subsequently continuously charged into the same twin-screw extruder as in Example 1 and heat-treated under the following conditions to obtain about 360 kg of indigestible dextrin with moisture content of 3.3%.

Speed of rotation: 150 r.p.m., with two screws rotated in the same direction

Inlet temperature: room temp. (about 20° C.)

Heating temperature: 200° C. (temp. of product at outlet)

Reaction time: 7 seconds

Example 3

Commercial potato starch (500 kg) was placed into a ribbon mixer, and 75 liters of 1% hydrochloric acid solution was sprayed onto the starch by pressurized air while rotating the mixer. The mixture then passed through a disintegrator to obtain a uniform mixture, which was further treated in the ribbon mixer for 1 hour. The mixture was pre-dried to a water content of about 6% by a flash dryer, subsequently continuously charged into the same twin-screw extruder as in Example 1 and heat-treated under the following conditions to obtain about 360 kg of indigestible dextrin with moisture content of 3.0%.

Speed of rotation: 135 r.p.m., with two screws rotated in the same direction

Inlet temperature: room temp. (about 20° C.)

Heating temperature: 140° C. (temp. of product at outlet)

Reaction time: 10 seconds

Example 4

Commercial potato starch (2,500 kg) was placed into a ribbon mixer, and 38 liters of 1% hydrochloric acid solution was sprayed onto the starch by pressurized air while rotating the mixer. The mixture then passed through a disintegrator to obtain a uniform mixture, which was further treated in the ribbon mixer for 1 hour. The mixture was pre-dried to a water content of about 5.5% by a flash dryer, subsequently continuously charged into a twin-screw extruder (Model TEX-95FC-23AW-2V for foods, manufactured by Japan Steel Works, Ltd. and having screws rotatable in same direction, 95 mm in diameter and 23/1 in length/diameter, drive motor 132 KW in output and rotatable at 300 r.p.m. max., aluminum cast heater, water cooling system and two vent holes) and heat-treated under the following conditions to obtain about 2,000 kg of indigestible dextrin with moisture content of 2.6%.

Speed of rotation: 180 r.p.m.

Inlet temperature: room temp. (about 20° C.)

Heating temperature: 170°˜180° C. (temp. of product at outlet)

Reaction time: 14.5 seconds

Example 5

Commercial potato starch (2,500 kg) was dried by a flash dryer to a water content of 5% and then placed into a ribbon mixer, and 178 liters of 1% hydrochloric acid solution was sprayed onto the starch by pressurized air while rotating the mixer. The mixture then passed through a disintegrator to obtain a uniform mixture, which was further treated in the ribbon mixer for 1 hour. The mixture was continuously charged into the same twin extruder as used in Example 4 and heat-treated under the following conditions to obtain about 2,100 kg of indigestible dextrin with moisture content of 3.1%.

Speed of rotation: 180 r.p.m.

Inlet temperature: room temp. (about 20° C.)

Heating temperature: 150°˜160° C. (temp. of product at outlet)

Reaction time: 72.5 seconds

The indigestible dextrins prepared from potato starch in Examples 1 to 5 were similarly analyzed by "Hakomori's methylation method" to determine contents of various glycosidic linkages and contents of indigestible components. Table 24 shows the results collectively.

                                      TABLE 24                                     __________________________________________________________________________     contents of linkages (%)                                                            Non-                       Content of                                     Example                                                                             reducing      1→4,                                                                       1→3,                                                                       1→2,                                                                           indigestible                                   No.  end  1→4                                                                        1→6                                                                        1→3                                                                        1→6                                                                        1→4                                                                        1→4                                                                        Others                                                                             component (%)                                  __________________________________________________________________________     1    24.2 45.0                                                                               8.6                                                                              5.2                                                                               9.4                                                                               1.4                                                                               2.9                                                                               3.3 68.0                                           2    25.9 35.6                                                                              10.8                                                                              7.3                                                                               9.2                                                                               1.3                                                                               2.7                                                                               7.2 82.0                                           3    27.1 29.1                                                                              12.5                                                                              8.9                                                                               10.3                                                                              1.5                                                                               3.1                                                                               8.5 86.7                                           4    28.2 28.8                                                                              15.6                                                                              8.8                                                                               5.6                                                                               1.5                                                                               2.7                                                                               8.8 88.1                                           5    26.1 39.4                                                                               9.2                                                                              6.6                                                                               8.6                                                                               1.4                                                                               3.0                                                                               5.7 73.4                                           __________________________________________________________________________

Next, the values given in Table 24 were substituted in the equations 1 to 30 listed in Table 6 to calculate contents Y of indigestible components. The results are summarized in Table 25 in terms of percent values.

                                      TABLE 25                                     __________________________________________________________________________                     Example                                                        Item            1   2    3    4    5                                           __________________________________________________________________________     Maximum variation range + (%)                                                                  6.3 -0.2 -0.8 -0.7 11.1                                        Maximum variation range - (%)                                                                  0.3 -11.7                                                                               -16.5                                                                               -11.5                                                                               0.8                                         Average variation range + (%)                                                                  2.7 --   --   --   3.1                                         Average variation range - (%)                                                                  -0.2                                                                               -4.0 -2.9 -3.2 --                                          Number of cases with variation                                                                 0   0    0    0    0                                           range of over +15.1%                                                           Number of cases with variation                                                                 0   0    0    0    1                                           range of +10.1% to +15%                                                        Number of cases with variation                                                                 27  0    0    0    29                                          range of 0.1% to +10%                                                          Number of cases with variation                                                                 1   0    0    0    0                                           range of 0%                                                                    Number of cases with variation                                                                 2   29   29   29   0                                           range of -0.1% to -10%                                                         Number of cases with variation                                                                 0   1    1    1    0                                           range of -10.1% to -15%                                                        Number of cases with variation                                                                 0   0    0    0    0                                           range of over -15.1%                                                           Number of cases with variation                                                                 27  27   27   29   28                                          range within ±5%                                                            Number of cases with variation                                                                 11  1    8    7    10                                          range within ±2%                                                            __________________________________________________________________________

With reference to Table 25, none of the five examples are outside the range of ±15% in the variation of the calculated value Y from the actual measurement. With respect to these examples, 29 to 30 cases among all the 30 cases are within the range of ±10%, 27 to 29 cases are within the range of ±5%, and 1 to 11 cases are within the range of ±2%. These results indicate that the equations of Table 6 represent a very high correlation and are also applicable to the examples.

Next, the results of the examples listed in Table 24 were substituted in Equation 31 to calculate the contents of indigestible components, which are shown in Table 26 in comparison with the corresponding measurements.

                  TABLE 26                                                         ______________________________________                                                Indigestible component                                                                                Range of                                                  Measured   Calculated                                                                               variation from                                   Example  (%)        (%)       measurement (%)                                  ______________________________________                                         1        68.0       70.0      +2.9                                             2        82.0       79.6      -2.9                                             3        86.7       83.8      -3.3                                             4        88.1       86.8      -1.5                                             5        73.4       76.9      +4.8                                             ______________________________________                                    

The variations of the calculated values from the measurements were in the range of +4.8% to -3.3%.

Similarly, the measured values of indigestible components of the examples were substituted in Equation 32 to calculate dietary fiber contents, which are shown in Table 27 in comparison with the measurements.

                  TABLE 27                                                         ______________________________________                                                Content of dietary fiber                                                                              Range of                                                  Measured   Calculated                                                                               variation from                                   Example  (%)        (%)       measurement (%)                                  ______________________________________                                         1        27.5       27.2      -1.1                                             2        38.8       38.8       0.0                                             3        43.0       43.0       0.0                                             4        45.4       44.3      -2.4                                             5        30.2       31.4      +3.9                                             ______________________________________                                    

Similarly, the measured values of indigestible components were substituted in Equation 33 to calculate caloric values 1, which are shown in Table 28 in comparison with the measurements.

                  TABLE 28                                                         ______________________________________                                                Caloric value-1                                                                                       Range of                                                  Measured   Calculated                                                                               variation from                                   Example  (%)        (%)       measurement (%)                                  ______________________________________                                         1        2.38       2.38      0.0                                              2        2.05       2.05      0.0                                              3        1.94       1.94      0.0                                              4        1.86       1.90      +2.2                                             5        2.32       2.25      -3.0                                             ______________________________________                                    

Similarly, the measured values of indigestible components of the examples were substituted in Equation 34 to calculate caloric values 2, which are shown in Table 29 in comparison with the measurements.

                  TABLE 29                                                         ______________________________________                                                Caloric value-2                                                                                       Range of                                                  Measured   Calculated                                                                               variation from                                   Example  (%)        (%)       measurement (%)                                  ______________________________________                                         1        1.96       1.96      0.0                                              2        1.54       1.54      0.0                                              3        1.40       1.40      0.0                                              4        1.31       1.36      +3.8                                             5        1.88       1.80      -4.2                                             ______________________________________                                    

With reference to Tables 27 to 29, the variations of the calculated values from the measurements are within the range of about 5%. This indicates that the values have a close correlation with the contents of indigestible components.

Example 6

A 2,000 kg quantity of the indigestible dextrin of Example 4 was dissolved in 4,000 liters of water, the solution neutralized to a pH of 5.8 with 1N aqueous solution of sodium hydroxide, 4kg of TERMAMYL 60L (liquid alpha-amylase, product of NOVO Industry Co., Ltd.) added to the solution, and the mixture was heated to about 95° C. for 15 minutes in an autoclave for hydrolysis. Next, fresh steam was introduced into the autoclave to heat the hydrolyzate, which was autoclaved at 125° C. for 3 minutes and then discharged into the atmosphere. 4 kg of TERMAMYL 60L was added again to the hydrolyzate as it cooled to a temperature of 85° C., followed by further hydrolysis for 20 minutes, introduction of fresh steam and autoclaving. The resulting hydrolyzate was discharged to the atmosphere, cooled to about 80° C., decolorized with activated carbon, filtered and subsequently desalted with a mixed bed of ion exchange resin, followed by decoloration with active carbon and filtration again. The filtrate was concentrated in a vacuum to a concentration of about 50% and then spray-dried, giving about 1,550 kg of refined indigestible dextrin with moisture content of 4.2%.

Example 7

A 2,000 kg quantity of the dextrin of Example 5 was dissolved in 4,000 liters of water, and the solution was neutralized to a pH of 5.8 with 1N aqueous solution of sodium hydroxide, heated in an autoclave with fresh steam introduced thereinto, autoclaved at 130° C. for 2 minutes, then discharged into the atmosphere and cooled to about 80° C. The resulting product was decolorized with active carbon, filtered, desalted with a mixed bed of ion exchange resin, decolored with active carbon again and filtered. The filtrate was concentrated in a vacuum to a concentration of about 50% and thereafter spray-dried, giving about 1,650 kg of refined indigestible dextrin with moisture content of 4.6%.

The indigestible dextrin of the present invention is usable for almost all foods. The term "foods" as used herein refers collectively to foods for man and feeds for livestock and for use in zoos and for pets. The indigestible dextrin is prepared from starch, is soluble in water, contains dietary fiber, and is usable also as a low calorie bulking agent in foods, so that it is usable in any food wherein dextrin and maltodextrin are usually usable. More specifically, the indigestible dextrin is effectively usable for liquid or powdery beverages such as coffee, black tea, cola and juice; baked products such as bread, cookies, crackers, cakes, pizza and pies; noodles such as wheat noodles, Chinese noodles and buckwheat noodles; pasta such as spaghetti, macaroni and fettuccine; confectionery such as candies, chocolate and chewing gum; doughnut, potato chips and like fried cakes or foods; ices such as ice cream, shakes and sherbets; daily products such as cream, cheese, milk powder, condensed milk, creamy powder, coffee whitener and milk beverages; chilled desserts such as custard pudding, yoghurt, drinkable yoghurt, jelly, mousse and Bavarian; retorted pouched or canned foods such as soups, stew, gratin and curries; seasonings such as bean paste, soy sauce, Worceter sauce, ketchup, mayonnaise, dressing, bouillon and roux; processed meat products such as ham, sausage, hamburger, meatball and corned beef, and these products as frozen; frozen processed foods such as pilafs, croquettes, omelets and doria; processed fishery products such as artificial boiled crab paste and boiled fish paste; processed agricultural products such as dried mashed potatoes, jam, marmalade, peanut butter and peanut; others including food boiled down in soy, rice cakes, rice snacks and fast foods; alcoholic beverages such as wines, cocktails, fizzes and liqueur; etc.

However, the dextrin is difficult to use in emulsified foods of the W/O type, such as margarin, since the dextrin incorporated therein is liable to separate off during preservation.

Further when serving as a low calorie bulking agent, the dextrin can be added to the food of the invention in an amount which is not limited insofar as the quality of the food is not impaired. However, if adults in good health take the low calorie bulking agent in an amount of 2 g/kg body weight by way of foods of the invention, diarrhea will occur in half of them, so that the amount of the agent to be taken is preferably not greater than half of this value, i.e., up to about 1 g/kg body weight.

Nevertheless, since the influence on physiological activities differs from person to person, it is most desirable to alter the amount in view of the effect achieved by the ingestion of the low calorie foods.

To check the indigestible dextrin for characteristics when it is used in foods, chiefly the product of Example 6 was used in the following experiments to obtain characteristic dats.

Experimental Example 12

A sensory test was conducted to determine the sweetness of the indigestible dextrin in comparison with that of other saccharides and maltodextrin of DE10, with the sweetness of sucrose taken as 100. Table 30 shows the result.

                  TABLE 30                                                         ______________________________________                                         Sample            Sweetness                                                    ______________________________________                                         Sugar             100                                                          Glucose           65                                                           Sorbitol          50                                                           Maltodextrin (DE10)                                                                              10                                                           Example 6         10                                                           Example 7         11                                                           ______________________________________                                    

The indigestible dextrin is about 10 in sweetness, tasting slightly sweet.

Experimental Example 13

A 30% solution of indigestible dextrin was checked for viscosity at temperatures of 10° to 80° C. using a Brookfield type viscosimeter. FIG. 1 shows the result along with the corresponding values of sucrose, gum arabic and maltodextrin.

The symbols in FIG. 1 stand for the following.

: indigestible dextrin of Example 6

: sucrose

: maltodextrin

◯: gum arabic

The indigestible dextrin is comparable to maltodextrin in voscosity. This indicates that the indigestible dextrin is usable in foods without entailing a great increase in viscosity.

Experimental Example 14

Coloration due to heating in the presence of amino acid

To 10% aqueous solution of indigestible dextrin was added 1% (based on solids) on glycine, and the mixture was heated at 100° C. for 150 minutes and checked for changes in the degree of coloration. The results achieved at pH of 4.5 and pH of 6.5 are shown in FIGS. 2 and 3, respectively. The same symbols as in FIG. 1 were used in these drawings.

The indigestible dextrin is not greatly different in the increase of coloration degree from glucose or maltose. This indicates that the indigestible dextrin is usable generally in the same manner as these materials.

Experimental Example 15

Freezing and thawing

A 30% aqueous solution of indigestible dextrin was subjected to five repeated freeze-thaw cycles and then checked for resulting turbidity. FIG. 4 shows the result along with the result achieved by maltodextrin. The symbols used in FIG. 4 have the same meaning as in FIG. 1.

The indigestible dextrin is much less than maltodextrin in increases in turbidity and is therefore very suitable for use in frozen foods.

Experimental Example 16

Freezing point depression

FIG. 5 shows the result obtained by checking 5 to 30% aqueous solutions of indigestible dextrin for freezing point depression along with the result achieved by sucrose and maltodextrin. The symbols in FIG. 5 are the same as in FIG. 1.

The indigestible dextrin is generally intermediate between sugar and maltodextrin in the degree of freezing point depression and is therefore suited to use in ices and the like.

Experimental Example 17

Hygroscopicity

The indigestible dextrin was made anhydrous by drying and then allowed to stand in a constant-humidity container at 20° C. and a relative humidity of 81%, 52% or 32% for 200 hours. FIG. 6 shows the hygroscopicity of the indigestible dextrin thus determined.

In FIG. 6, the results obtained at R. H. 81%, R. H. 52% and R. H. 32% are indicated at (1), (2) and (3), respectively.

The water content of the indigestible dextrin will not exceed 18% even if preserved for a long period of time. The indigestible dextrin is therefore suited to use in powdery foods.

Experimental Example 18

Mixography

To investigate the behavior of the indigestible dextrin for use in foods having wheat flour incorporated therein, mixograms were prepared using the mixes given in Table 31. FIGS. 7 to 9 show the results. FIG. 7 shows a control mix; FIG. 8, a sugar mix and FIG. 9, an indigestible dextrin mix (low calorie mix containing dietary fiber).

                  TABLE 31                                                         ______________________________________                                                   Control   Sugar   Dietary fiber                                      ______________________________________                                         Hard flour (g)                                                                             35.0        35.0    35.0                                           Sugar (g)   --          1.75    --                                             Example 6 (g)                                                                              --          --      1.75                                           Water (g)   26.0        25.5    25.5                                           Ratio of water                                                                             74.3        72.9    72.9                                           added (%)                                                                      Developping 4.5         4.0     5.5                                            time (min)                                                                     ______________________________________                                    

In the case where the indigestible dextrin was used in place of sucrose, the mix became viscoelastic with a 1.5 minute delay. It was therefore found necessary to lengthen the dough mixing time, to age the dough for a longer period of time or to add the indigestible dextrin during mixing.

Examples of foods embodying the invention will be described next. The indigestible dextrin used will be referred to by the number of example in which it was prepared. The amounts of ingredients and dietary fiber are expressed in grams.

Example 8

Food example 1

Black tea of the composition given in Table 32 was prepared.

                  TABLE 32                                                         ______________________________________                                         Black tea         Control  Example                                             ______________________________________                                         Black tea extract 97.0     97.0                                                Sugar             3.0      3.0                                                 Dextrin (Example 7)                                                                              --       10.0                                                Dietary fiber     0        2.88                                                Dietary fiber/240 g                                                                              0        6.28                                                ______________________________________                                    

Example 9

Food example 2

Cola drink of the composition given in Table 33 was prepared.

                  TABLE 33                                                         ______________________________________                                         Cola drink        Control  Example                                             ______________________________________                                         Sugar             11.0     11.0                                                Cola base         0.3      0.3                                                 Citric acid       0.05     0.05                                                Soda water        88.65    88.65                                               Dextrin (Example 6)                                                                              --       12.0                                                Dietary fiber     0        5.22                                                Dietary fiber/240 g                                                                              0        11.2                                                ______________________________________                                    

Example 10

Food example 3

Orange juice (30%) was prepared according to the recipe given in Table 34 dissolving powdery ingredients in water, adding condensed juice and flavoring to the solution and homogenizing the mixture by a homomixer.

                  TABLE 34                                                         ______________________________________                                         Orange juice (30%)                                                                               Control  Example                                             ______________________________________                                         Orange juice      6.7      6.7                                                 concentrate (BX.45)                                                            Sugar             8.1      8.1                                                 Citric acid       0.3      0.3                                                 Sodium citrate    0.1      0.1                                                 Orange flavor     0.3      0.3                                                 Water             84.5     84.5                                                Dextrin (Example 6)                                                                              --       5.0                                                 Dietary fiber     0.07     2.25                                                Dietary fiber/240 g                                                                              0.17     5.14                                                ______________________________________                                    

Example 11

Food example 4

A sports drink was prepared by mixing all ingredients with water according to the recipe of Table 35 and sterilizing the mixture by heating.

                  TABLE 35                                                         ______________________________________                                         Sports drink       Control  Example                                            ______________________________________                                         Salt               0.5      0.5                                                Vitamin C          0.03     0.03                                               Vitamin B.sub.1.Sodium salt                                                                       0.03     0.03                                               Magnesium chloride 0.2      0.2                                                Calcium lactate    0.2      0.2                                                Citric acid        2.4      2.4                                                Sodium citrate     1.7      1.7                                                Flavor             2.0      2.0                                                Dextrose           80.0     80.0                                               Fructose           12.94    12.94                                              Water              1500.0   1500.0                                             Dextrin (Example 7)                                                                               --       80.0                                               Total              1600.0   1680.0                                             Dietary fiber      0        23.0                                               Dietary fiber/240 g                                                                               0        3.29                                               ______________________________________                                    

Example 12

Food example 5

According to the recipe of Table 36, a milk shake was prepared by mixing all ingredients with water, heating the mixture to 80° C. for dissolving, homogenizing the butter by a homogenizer, aging the mixture overnight at 5° C., then freezing the mixture, thereafter rapidly cooling the mixture to -40° C. and fully shaking the mixture.

                  TABLE 36                                                         ______________________________________                                         Milk shake         Control  Example                                            ______________________________________                                         Butter             5.6      1.7                                                Skimmed milk       10.5     5.5                                                Dextrin (Example 6)                                                                               --       17.65                                              Sugar              9.0      --                                                 Aspartame          --       0.05                                               Milk flavor        --       0.1                                                Butter flavor      --       0.1                                                Sorbitol           4.0      4.0                                                Emulsifier         0.7      0.7                                                Water              70.2     70.2                                               Dietary fiber      0.1      7.73                                               Dietary fiber/250 g                                                                               0.25     19.3                                               Caloric val.1(KCal/100 g)                                                                         129      81                                                 Caloric val.2(KCal/100 g)                                                                         129      71                                                 ______________________________________                                    

Example 13

Food example 6

According to the recipe of Table 37, ice cream was prepared by mixing all ingredients together, heating the mixture to 70° C., stirring the mixture by a homomixer, thereafter homogenizing the mixture by a homogenizer, aging the mixture in a refrigerator for 1 day, freezing the mixture and thereafter rapidly cooling the mixture to -40° C.

                  TABLE 37                                                         ______________________________________                                         Ice cream          Control  Example                                            ______________________________________                                         Butter             15.0     7.5                                                Skimmed milk       10.0     5.0                                                Sugar              10.0     --                                                 Dextrin (Example 6)                                                                               --       24.27                                              Emulsifier         0.7      0.7                                                Milk flavor        --       0.1                                                Cream flavor       --       0.1                                                Water              57.3     57.3                                               Aspartame          --       0.03                                               Sorbitol           --       5.0                                                Maltodextrin (DE 8)                                                                               7.0      --                                                 Dietary fiber      0.09     10.6                                               Dietary fiber/150 g                                                                               0.14     15.9                                               Caloric val.1(KCal/100 g)                                                                         216      136                                                Caloric val.2(KCal/100 g)                                                                         216      124                                                ______________________________________                                    

Example 14

Food example 7

According to the recipe of Table 38, skimmed milk, as fermented and ground, was mixed with other ingredients, and the mixture was treated by a homogenizer to prepare a yoghurt drink.

                  TABLE 38                                                         ______________________________________                                         Yoghurt (Soft)     Control  Example                                            ______________________________________                                         Fermented skimmed milk                                                                            40.0     40.0                                               Sugar              14.0     13.0                                               Stabilizer         0.35     0.35                                               Flavor             0.05     0.05                                               Water              45.6     42.6                                               Dextrin (Example 7)                                                                               --       10.0                                               Dietary fiber      0.06     2.94                                               Dietary fiber/240 g                                                                               0.06     6.66                                               ______________________________________                                    

Example 15

Food example 8

According to the recipe of Table 39, hard yogurt was prepared by adding a hardening agent to skimmed milk, innoculating the mixture with 3% of starter, refrigerating the mixture when acidity of 0.7% was attained, mixing the mixture with other ingredients by stirring and refrigerating the resulting mixture again.

                  TABLE 39                                                         ______________________________________                                         Yoghurt (Hard)    Control   Example                                            ______________________________________                                         Skimmed milk      90.9      90.9                                               Sugar             9.1       --                                                 Dextrin (Example 6)                                                                              --        9.1                                                Stevioside        --        0.05                                               Flavor            Small amt.                                                                               Small amt.                                         Gelatin           Small amt.                                                                               Small amt.                                         Dietary fiber     0.07      3.96                                               Dietary fiber/150 g                                                                              0.1       6.94                                               Caloric val.1(KCal/100 g)                                                                        64        45                                                 Caloric val.2(KCal/100 g)                                                                        64        41                                                 ______________________________________                                    

Example 16

Food example 9

According to the recipe of Table 40, a powder of coffee whitener was prepared by dissolving water-soluble ingredients in 66.6% of hot water based on the dry weight of the ingredients, dissolving an emulsifying agent in oil, mixing together and homogenizing the two solutions at 60° C. to obtain an emulsion, and thereafter spray-drying the emulsion.

                  TABLE 40                                                         ______________________________________                                         Coffee whitener    Control  Example                                            ______________________________________                                         Hardened soy bean oil                                                                             50.0     50.0                                               Corn sirup solid (DE 40)                                                                          49.0     --                                                 Emulsifier         0.84     0.84                                               Cream flavor       0.16     0.16                                               Dextrin (Example 6)                                                                               --       49.0                                               Dietary fiber      0        23.5                                               Dietary fiber/12 g 0        2.82                                               Caloric val.1(KCal/100 g)                                                                         647      549                                                Caloric val.2(KCal/100 g)                                                                         647      523                                                ______________________________________                                    

Example 17

Food example 10

Candy was prepared by dissolving the ingredients of Table 41 other than the flavoring in water, concentrating the solution to Bx 80°, boiling down the concentrate by an evaporator, cooling the resulting concentrate to 40° C., admixing the flavor therewith and molding the mixture.

                  TABLE 41                                                         ______________________________________                                         Candy              Control  Example                                            ______________________________________                                         Corn sirup         49.4     24.7                                               Citric acid        0.5      0.5                                                Flavor             0.1      0.1                                                Sugar              50.0     20.0                                               Dextrin (Example 7)                                                                               --       54.6                                               Stevioside         --       0.1                                                Dietary fiber      0        15.7                                               Dietary fiber/12 g 0        1.89                                               Caloric val.1(KCal/100 g)                                                                         359      284                                                Caloric val.2(KCal/100 g)                                                                         359      261                                                ______________________________________                                    

Example 18

Food example 11

The ingredients of Table 42 other than the carbohydrates and flavor were placed into a pan, heated for melting and thoroughly mixed together. Chewing gum was prepared by admixing the carbohydrates with the mixture as cooled to 50° C., followed by addition of the flavor at 40° C., molding and standing for cooling.

                  TABLE 42                                                         ______________________________________                                         Chewing gum        Control  Example                                            ______________________________________                                         Poly-Vinylacetate  20.0     20.0                                               Plasticizer        3.0      3.0                                                Poly-isobutyrene   3.0      3.0                                                Micro-crystalline wax                                                                             2.0      2.0                                                Calcium carbonate  2.0      2.0                                                Sugar (powder)     45.0     --                                                 Dextrose           24.0     --                                                 Dextrin (Example 7)                                                                               --       68.7                                               Aspartame          --       0.3                                                Flavor             1.0      1.0                                                Dietary fiber      0        19.8                                               Dietary fiber/32 g 0        6.33                                               Caloric val.1(KCal/100 g)                                                                         270      162                                                Caloric val.2(KCal/100 g)                                                                         270      133                                                ______________________________________                                    

Example 19

Food example 12

All ingredients of Table 43 were thoroughly mixed together at 40° C. and further kneaded in an attritor for a long period of time to pulverize the particles, followed by molding and cooling to prepare a sweet chocolate.

                  TABLE 43                                                         ______________________________________                                         Sweet chocolate    Control  Example                                            ______________________________________                                         Bitter chocolate   33.2     33.2                                               Sugar              55.4     --                                                 Dextrin (Example 6)                                                                               --       54.4                                               Aspartame          --       0.31                                               cacao butter       11.1     11.1                                               Dietary fiber      0.0      23.7                                               Dietary fiber/100 g                                                                               0.0      23.7                                               Caloric val.1(KCal/100 g)                                                                         450      347                                                Caloric val.2(KCal/100 g)                                                                         450      317                                                ______________________________________                                    

Example 20

Food example 13

According to the recipe of Table 44, wheat flour, processed starch and egg yolk powder were admixed with a small amount of water. A solution of the other materials as dissolved in the remaining portion of water at 80° C. was added to the mixture while using a whip, and the resulting mixture was boiled on an intense fire to prepare custard cream.

                  TABLE 44                                                         ______________________________________                                         Custard cream      Control  Example                                            ______________________________________                                         Sugar              13.5     --                                                 Dextrose           9.0      --                                                 Corn sirup (DE 40) 12.3     6.2                                                Water              41.0     41.9                                               Dextrin (Example 7)                                                                               --       31.59                                              Stevioside         --       0.11                                               Wheat flour        3.8      3.8                                                Modified starch    7.0      7.0                                                Skimmed milk       1.3      1.3                                                Margarine          11.9     7.9                                                Egg yolk powder    0.2      0.2                                                Dietary fiber      0.092    9.19                                               Dietary fiber/50 g 0.046    4.60                                               Caloric val.1(KCal/100 g)                                                                         258      195                                                Caloric val.2(KCal/100 g)                                                                         258      182                                                ______________________________________                                    

Example 21

Food example 14

According to the recipe of Table 45, gelatine was dissolved in 254 g of water, and all the other ingredients except aspartame were dissolved in the remaining portion of water. The solutions were cooled to 40° C., then all the ingredients were mixed together, and the resulting mixture was refrigerated to prepare an orange jelly.

                  TABLE 45                                                         ______________________________________                                         Orange gelly       Control  Example                                            ______________________________________                                         Sugar              20.8     --                                                 Dextrin (Example 6)                                                                               --       20.8                                               Aspartame          --       0.11                                               Water              34.7     34.7                                               Gelatine           2.8      2.8                                                Orange juice       31.2     31.2                                               Curacao            10.4     10.4                                               Dietary fiber      0.09     9.14                                               Dietary fiber/100 g                                                                               0.09     9.14                                               Caloric val.1(KCal/100 g)                                                                         131      88                                                 Caloric val.2(KCal/100 g)                                                                         131      77                                                 ______________________________________                                    

Example 22

Food example 15

According to the recipe of Table 46, the ingredients other than pectin were mixed together, lightly crushed by a mixer and then heated on a low fire. Upon evaporation of 20% of the water, pectin was added to the mixture, followed by cooling to prepare strawberry jam.

                  TABLE 46                                                         ______________________________________                                         Strawberry jam     Control  Example                                            ______________________________________                                         Flesh strawberry   55.0     55.0                                               Sugar              45.0     --                                                 Dextrin (Example 6)                                                                               --       45.0                                               Pectin             0.1      0.1                                                Citric acid        0.1      0.1                                                Aspartame          --       0.25                                               Dietary fiber      0.93     20.5                                               Dietary fiber/30 g 0.28     6.15                                               Caloric val.1(KCal/100 g)                                                                         266      139                                                Caloric val.2(KCal/100 g)                                                                         266      106                                                ______________________________________                                    

Example 23

Food example 16

According to the recipe of Table 47, granulated sugar, water and indigestible dextrin were added to pared apples, and the mixture was boiled on a medium fire. When the apples became semi-transparent, lemon juice was added to the mixture, followed by boiling down on a medium fire without scorching. When the apples became soft, the mixture was strained and further boiled down to Bx 70° to prepare apple jam.

                  TABLE 47                                                         ______________________________________                                         Apple jam          Control  Example                                            ______________________________________                                         Flesh apple        55.4     55.4                                               Sugar              24.0     24.0                                               Lemon juice        2.2      2.2                                                Water              18.4     18.4                                               Dextrin (Example 6)                                                                               --       10.0                                               Dietary fiber      0.88     5.24                                               Dietary fiber/30 g 0.58     3.15                                               ______________________________________                                    

Example 24

Food example 17

According to the recipe of Table 48, the whole amount of indigestible dextrin and stevioside were added to 30 g of water to prepare a syrup, which was then heated. When the syrup became boiled up, bean paste was added thereto. The mixture was boiled down to an amount weighing 100 g to prepare bean jam.

                  TABLE 48                                                         ______________________________________                                         Bean jam           Control  Example                                            ______________________________________                                         Bean paste         59.0     59.0                                               Sugar              41.0     --                                                 Dextrin (Example 7)                                                                               --       40.77                                              Stevioside         --       0.23                                               Dietary fiber      4.20     16.0                                               Dietary fiber/100 g                                                                               4.20     16.0                                               Caloric val.1(KCal/100 g)                                                                         249      182                                                Caloric val.2(KCal/100 g)                                                                         249      165                                                ______________________________________                                    

Example 25

Food example 18

According to the recipe given in Table 49, 23.6 g of water, indigestible dextrin and stevioside were added to agar swollen with water, and the mixture was heated for boiling and dissolving, strained and then boiled again, followed by addition of bean paste. The mixture was boiled down to an amount weighing 100 g, then moled and cooled to prepare a sweet jelly of beans.

                  TABLE 49                                                         ______________________________________                                         Sweet jelly of beans                                                                              Control  Example                                            ______________________________________                                         Bean paste         36.8     36.8                                               Agar-agar          0.8      0.8                                                Water              7.2      7.2                                                Sugar              55.2     --                                                 Dextrin (Example 7)                                                                               --       54.9                                               Stevioside         --       0.3                                                Dietary fiber      2.65     18.5                                               Dietary fiber/40 g 1.06     7.38                                               Caloric val.1(KCal/100 g)                                                                         269      180                                                Caloric val.2(KCal/100 g)                                                                         269      157                                                ______________________________________                                    

Example 26

Food example 19

A cereal was dipped in a solution of indigestible dextrin, Bx 50°, according to the recipe of Table 50 and dried overnight at 40° C. to prepare a processed cereal. The product was glossier than a control, and the original water retentivity of 2.7% increased to 7.0%.

                  TABLE 50                                                         ______________________________________                                         Cereal             Control  Example                                            ______________________________________                                         Cereal             100.0    53.8                                               Dextrin (Example 6)                                                                               --       42.6                                               Dietary fiber      2.90     20.1                                               Dietary fiber/40 g 1.16     8.04                                               Caloric val.1(KCal/100 g)                                                                         389      285                                                Caloric val.2(KCal/100 g)                                                                         389      263                                                ______________________________________                                    

Example 27

Food example 20

According to the recipe given in Table 51, indigestible dextrin was uniformly kneaded with wheat flour and further kneaded therewith while adding water in small portions to prepare spaghetti.

                  TABLE 51                                                         ______________________________________                                         Spaghetti          Control  Example                                            ______________________________________                                         Wheat flour        100.0    100.0                                              Water              30.0     25.0                                               Dextrin (Example 6)                                                                               --       5.0                                                Dietary fiber      2.10     4.28                                               Dietary fiber/200 g                                                                               3.23     6.58                                               ______________________________________                                    

Example 28

Food example 21

The ingredients of Table 52 were fully kneaded together to obtain dough, which was then fermented and baked to prepare loaves of bread.

                  TABLE 52                                                         ______________________________________                                         White bread        Control  Example                                            ______________________________________                                         Wheat flour        100.0    100.0                                              Water              61.0     61.0                                               Baker's yeast      3.0      3.0                                                Salt               2.0      2.0                                                Sugar              6.0      6.0                                                Skimmed milk       3.0      3.0                                                Shortening         5.0      5.0                                                Dextrin (Example 6)                                                                               --       5.0                                                Dietary fiber/180 g                                                                               2.13     4.31                                               ______________________________________                                    

Example 29

Food example 22

According to the recipe of Table 53, milk and eggs were added to wheat flour, and the other ingredients were added to the mixture with kneading to obtain uniform dough, which was then molded and fried in oil at 160° to 180° C. while turning the molded pieces upside down. The fried pieces were drained off the oil to obtain American doughnut.

                  TABLE 53                                                         ______________________________________                                         American dough-nut Control  Example                                            ______________________________________                                         Wheat flour        100.0    100.0                                              Sugar              29.2     29.2                                               Egg (Whole)        22.2     22.2                                               Milk               40.2     40.2                                               Butter             5.0      5.0                                                Salt               0.2      0.2                                                Lemon flavor       0.2      0.2                                                Baking powder      3.0      3.0                                                Dextrin (Example 7)                                                                               --       20.0                                               Dietary fiber      2.20     7.96                                               Dietary fiber/100 g                                                                               1.10     3.62                                               ______________________________________                                    

Example 30

Food example 23

According to the recipe of Table 54, egg white and water were fully mixed together to obtain a whipped mixture, to which indigestible dextrin, Avicel and hard wheat flour were successively added with kneading to prepare a uniform mixture. The mixture was freeze-dried to avoid thermal denaturation of the egg white and prepare a replacer for wheat flour.

                  TABLE 54                                                         ______________________________________                                         Wheat flour replacer                                                                              Control  Example                                            ______________________________________                                         Soft wheat flour   100.0    --                                                 Dextrin (Example 6)                                                                               --       40.0                                               Egg white          --       10.0                                               Water              --       10.0                                               Avicel             --       25.0                                               Hard wheat flour   --       15.0                                               Dietary fiber      2.10     42.8                                               Caloric val.1(KCal/100 g)                                                                         368      165                                                Caloric val.2(KCal/100 g)                                                                         368      143                                                ______________________________________                                    

Example 31

Food example 24

All ingredients listed in Table 55 and including the flour replacer of food example 23 were kneaded together. The mixture, when becoming elastic, was spread out flat and blanked out. The resulting pieces were baked at 190° C. for 10 minutes, affording butter cookies.

                  TABLE 55                                                         ______________________________________                                         Butter cookie      Control  Example                                            ______________________________________                                         Wheat flour        47.6     --                                                 Wheat flour replacer                                                                              --       47.6                                               Sugar              19.1     --                                                 Dextrin (Example 6)                                                                               --       27.0                                               Stevioside         --       0.1                                                Shortening         21.4     13.4                                               Water              11.9     11.9                                               Dietary fiber      1.00     32.1                                               Dietary fiber/30 g 0.30     9.64                                               Caloric val.1(KCal/100 g)                                                                         446      250                                                Caloric val.2(KCal/100 g)                                                                         446      226                                                ______________________________________                                    

Example 32

Food example 25

According to the recipe of Table 56, all ingredients including the flour replacer of food example 23 were mixed with water and treated with a whip for stirring and dissolving to obtain uniform dough, which was then baked at 180° C. for 50 minutes to prepare a pound cake.

                  TABLE 56                                                         ______________________________________                                         Pound cake         Control  Example                                            ______________________________________                                         Wheat flour        23.0     --                                                 Wheat flour replacer                                                                              --       23.0                                               Sugar              28.8     --                                                 Dextrin (Example 7)                                                                               --       37.3                                               Stevioside         --       0.1                                                Egg (whole)        17.2     17.2                                               Milk               6.9      6.9                                                Shortening         17.2     8.6                                                Water              6.9      6.9                                                Dietary fiber      0.51     20.6                                               Dietary fiber/100 g                                                                               0.51     20.6                                               Caloric val.1(KCal/100 g)                                                                         386      232                                                Caloric val.2(KCal/100 g)                                                                         386      211                                                ______________________________________                                    

Example 33

Food example 26

According to the recipe of Table 57, all ingredients including the flour replacer of food example 23 were mixed with water, and the mixture was stirred with a whip to incorporate foams into the mixture. The mixture was baked at 180° C. for 40 minutes to prepare a sponge cake.

                  TABLE 57                                                         ______________________________________                                         Sponge cake        Control  Example                                            ______________________________________                                         Wheat flour        33.3     --                                                 Wheat flour replacer                                                                              --       33.3                                               Sugar              33.4     --                                                 Egg (whole)        33.3     33.3                                               Dextrin (Example 7)                                                                               --       33.3                                               Stevioside         --       0.1                                                Dietary fiber      0.73     23.9                                               Dietary fiber/100 g                                                                               0.73     23.9                                               Caloric val.1(KCal/100 g)                                                                         305      183                                                Caloric val.2(KCal/100 g)                                                                         305      162                                                ______________________________________                                    

Example 34

Food example 27

According to the recipe of Table 58, crust dough was prepared by full kneading and repeated folding. The inner ingredient was boiled down until it became half-deformed. The dough and inner ingredient were molded and then baked to prepare an apple pie.

                  TABLE 58                                                         ______________________________________                                         Sponge cake        Control  Example                                            ______________________________________                                         Soft wheat flour   100.0    100.0                                              Hard wheat flour   100.0    100.0                                              Butter             180.0    180.0                                              Water              105.0    105.0                                              Apple              300.0    300.0                                              Sugar              90.0     90.0                                               Cinnamon powder    1.0      1.0                                                Egg yolk           10.0     10.0                                               Dextrin (Example 6)                                                                               --       40.0                                               Dietary fiber      9.01     26.4                                               Dietary fiber(1/6) 1.50     4.40                                               ______________________________________                                    

Example 35

Food example 28

According to the recipe of Table 59, corn cream soup was prepared by boiling corn in water until no unboiled portion remained, then adding the other ingredients and boiling down the mixture.

                  TABLE 59                                                         ______________________________________                                         Corn cream soup    Control  Example                                            ______________________________________                                         Milk               19.8     19.8                                               Sweet corn         18.4     18.4                                               Butter             2.3      2.3                                                Wheat flour        2.0      2.0                                                Salt               1.0      1.0                                                Seasonings         0.2      0.2                                                Spices             0.2      0.2                                                Water              56.1     56.1                                               Dextrin (Example 7)                                                                               --       6.0                                                Dietary fiber      0.45     2.18                                               Dietary fiber/200 g                                                                               0.90     4.11                                               ______________________________________                                    

Example 36

Food example 29

According to the recipe given in Table 60, spare rib was pan-fried and placed into another pan. Vegetables were also pan-fried and transferred onto the pan. Wheat flour and curry powder were pan-fried into a brown roux. All the ingredients were boiled down in the pan to prepare a retorted curry.

                  TABLE 60                                                         ______________________________________                                         Retorted pauch curry                                                                              Control  Example                                            ______________________________________                                         Spare rib          12.4     12.4                                               Salt               0.5      0.5                                                Butter             6.2      5.2                                                Water              49.0     49.0                                               Potato             12.4     8.4                                                Onion              12.4     12.4                                               Carrot             2.5      2.5                                                Wheat flour        3.6      3.6                                                Curry powder       0.5      0.5                                                Spices             0.5      0.5                                                Dextrin (Example 6)                                                                               --       5.0                                                Dietary fiber      0.57     2.69                                               Dietary fiber/200 g                                                                               1.14     5.38                                               ______________________________________                                    

Example 37

Food example 30

According to the recipe of Table 61, meat was fully pan-fried and then placed into another pan. Vegetables, especially onions, were fully pan-fried. All the ingredients were then boiled down in the pan for 3 hours to prepare beef stew.

                  TABLE 61                                                         ______________________________________                                         Beef stew          Control  Example                                            ______________________________________                                         Spare rib          15.5     15.5                                               Salt               0.2      0.2                                                Wheat flour        2.7      2.7                                                Salad oil          3.9      3.9                                                Onion              9.7      9.7                                                Potato             13.6     13.6                                               Carrot             5.8      5.8                                                Green beans        1.9      1.9                                                Seasoning (liquid) 38.8     38.8                                               Butter             1.9      1.9                                                Tomato puree       5.8      5.8                                                White pepper       0.2      0.2                                                Dextrin (Example 6)                                                                               --       5.0                                                Dietary fiber      0.78     2.96                                               Dietary fiber/300 g                                                                               2.34     8.46                                               ______________________________________                                    

Example 38

Food example 31

Non-oil dressing was prepared according to the recipe of Table 62 by mixing liquid ingredients together and thereafter dissolving powder ingredients in the mixture.

                  TABLE 62                                                         ______________________________________                                         Non-oil dressing   Control  Example                                            ______________________________________                                         Vinegar            30.8     30.8                                               Sugar              4.0      4.0                                                Salt               0.5      0.5                                                Soy-sauce          8.4      8.4                                                Seasoning (liquid) 26.3     26.3                                               Corn sirup solid   30.0     --                                                 Dextrin (Example 6)                                                                               --       30.0                                               Dietary fiber      0        13.1                                               Dietary fiber/20 g 0        2.61                                               Caloric val.1(KCal/100 g)                                                                         163      102                                                Caloric val.2(KCal/100 g)                                                                         163      86                                                 ______________________________________                                    

Example 39

Food example 32

According to the recipe of Table 63, powder ingredients other than Xanthan gum were dissolved in water, and the solution was heated to 80° C. Upon the solution reaching 40° C., vinegar was added, and the mixture was treated by a homomixer driven at a medium speed while adding salad oil in small portions to the mixture to obtain an emulsion. Xanthan gum was dissolved in the emulsion with the homomixer driven at a low speed to prepare dressing of the emulsion type.

                  TABLE 63                                                         ______________________________________                                         Dressing           Control  Example                                            ______________________________________                                         Salad oil          30.0     15.0                                               Emulstar #30       3.0      3.0                                                Xanthan gum        0.2      0.2                                                Vinegar            15.0     15.0                                               Salt               1.3      1.3                                                Sugar              2.7      2.7                                                Dextrin (Example 7)                                                                               --       10.5                                               Water              47.8     52.3                                               Dietary fiber      0.2      3.22                                               Dietary fiber/20 g 0.04     0.64                                               Caloric val.1(KCal/100 g)                                                                         301      186                                                Caloric val.2(KCal/100 g)                                                                         301      181                                                ______________________________________                                    

"Emulster #30" listed in Table 63 is a lipophilic modified starch (product of Matsutani Chemical Industry Co., Ltd.).

Example 40

Food example 33

According to the recipe of Table 64, powder ingredients were dissolved in water and vinegar, and egg yolk was admixed with the solution. The mixture was treated by a homomixer driven at a medium speed while adding salad oil thereto in small portions for emulsification to prepare mayonnaise.

                  TABLE 64                                                         ______________________________________                                         Mayonnaise         Control  Example                                            ______________________________________                                         Salad oil          70.0     35.0                                               Vinegar            10.0     10.0                                               Egg yolk           17.5     10.0                                               Salt               1.5      1.5                                                Sugar              1.0      1.0                                                Dextrin (Example 6)                                                                               --       25.0                                               Water              --       17.5                                               Dietary fiber      0.02     10.9                                               Dietary fiber/20 g 0.004    2.18                                               Caloric val.1(KCal/100 g)                                                                         714      409                                                Caloric val.2(KCal/100 g)                                                                         714      395                                                ______________________________________                                    

Example 41

Food example 34

Peanut butter was prepared according to the recipe of Table 65 by crushing raw peanut, crushing the peanut with an attritor and admixing other ingredients therewith.

                  TABLE 65                                                         ______________________________________                                         Peanut Butter      Control  Example                                            ______________________________________                                         Peanut             50.0     33.0                                               Palm oil           50.0     33.0                                               Dextrin (Example 6)                                                                               --       33.9                                               Peanut flavor      --       0.1                                                Dietary fiber      4.35     17.6                                               Dietary fiber/20 g 0.87     3.52                                               Caloric val.1(KCal/100 g)                                                                         741      550                                                Caloric val.2(KCal/100 g)                                                                         741      532                                                ______________________________________                                    

Example 42

Food example 35

The powder ingredients listed in the recipe of Table 66 were uniformly mixed together to prepare cheese powder.

                  TABLE 66                                                         ______________________________________                                         Cheese powder      Control  Example                                            ______________________________________                                         Cheese powder      100.0    50.0                                               Dextrin (Example 7)                                                                               --       49.9                                               Cheese flavor      --       0.1                                                Dietary fiber      0.60     14.1                                               Dietary fiber/10 g 0.06     1.47                                               Caloric val.1(KCal/100 g)                                                                         562      392                                                Caloric val.2(KCal/100 g)                                                                         562      371                                                ______________________________________                                    

Example 43

Food example 36

According to the recipe of Table 67, lactobacillus starter and rennet were added to a mixture of fresh cream and indigestible dextrin, followed by standing at 20° C. for 15 hours. With addition of a flavor, the mixture was kneaded in an attritor and then cooled to prepare cream cheese.

                  TABLE 67                                                         ______________________________________                                         Cream cheese       Control  Example                                            ______________________________________                                         Flesh cream        100.0    50.0                                               Dextrin (Example 6)                                                                               --       35.0                                               Water              --       14.8                                               Lactobacillus starter                                                                             1.0      1.0                                                Rennet             0.01     0.01                                               Cheese oil         --       0.1                                                Cream flavor       --       0.1                                                Dietary fiber      0.0      15.2                                               Dietary fiber/20 g 0.0      3.05                                               Caloric val.1(KCal/100 g)                                                                         431      280                                                Caloric val.2(KCal/100 g)                                                                         431      261                                                ______________________________________                                    

Example 44

Food example 37

White sauce was prepared according to the recipe of Table 68 by pan-frying soft wheat flour in butter, then mixing other ingredients therewith and boiling down the mixture until the mixture became thickened.

                  TABLE 68                                                         ______________________________________                                         White sauce        Control  Example                                            ______________________________________                                         Butter             8.0      4.0                                                Dextrin (Example 7)                                                                               --       4.0                                                Water              --       35.9                                               Soft wheat flour   9.0      --                                                 Hard wheat flour   --       7.0                                                Milk               68.0     34.0                                               Milk flavor        --       0.1                                                Seasoning (liquid) 13.9     13.9                                               Salt               1.0      1.0                                                White pepper       0.1      0.1                                                Dietary fiber      0.33     1.37                                               Caloric val.1(KCal/100 g)                                                                         134      86                                                 Caloric val.2(KCal/100 g)                                                                         134      84                                                 ______________________________________                                    

Example 45

Food example 38

Meat sauce was prepared according to the recipe of Table 69 by pan-frying minced pork, onions and carrots in fat, pan-frying these ingredients again with addition of wheat flour, admixing other ingredients with the mixture and boiling down the resulting mixture until the mixture became thickened.

                  TABLE 69                                                         ______________________________________                                         Meat sauce         Control  Example                                            ______________________________________                                         Poke (minced)      8.2      8.2                                                Fat (cow)          5.0      --                                                 Dextrin (Example 6)                                                                               --       5.0                                                Water              16.0     16.0                                               Onion              30.0     30.0                                               Carrot             6.0      6.0                                                Tomato ketchap     8.5      8.5                                                Tomato puree       8.5      8.5                                                Apple (boiled)     12.5     12.5                                               Sugar              1.7      1.7                                                Salt               0.8      0.8                                                Spices and seasonings                                                                             1.8      1.8                                                Wheat flour        1.0      1.0                                                Dietary fiber      0.98     3.16                                               Dietary fiber/100 g                                                                               0.98     3.16                                               Caloric val.1(KCal/100 g)                                                                         105      74                                                 Caloric val.2(KCal/100 g)                                                                         105      71                                                 ______________________________________                                    

Example 46

Food example 39

Sausage of beef and pork was prepared according to the recipe of Table 70 by crushing raw ingredients to prepare a mixture, filling the mixture into a film bag, allowing the mixture to stand as salt-pickled at 5° C. for 12 hours and thereafter boiling the mixture at 75° C. for 90 minutes, followed by refrigeration.

                  TABLE 70                                                         ______________________________________                                         Beef and poke sausage                                                                             Control  Example                                            ______________________________________                                         Beef               22.0     22.0                                               Ice                17.29    17.29                                              Salt               1.7      1.7                                                Pickles            0.01     0.01                                               Sugar              1.0      1.0                                                Sodium glutamate   0.5      0.5                                                Spices             0.5      0.5                                                Potato starch      3.0      3.0                                                Poke (shoulder)    54.0     5 .0                                               Dextrin (Example 6)                                                                               --       10.0                                               Dietary fiber      0.20     4.55                                               Dietary fiber/100 g                                                                               0.20     4.14                                               ______________________________________                                    

Example 47

Food example 40

Corned beef was prepared from beef as held in a salt pickling solution for 5 days and boiled at 115° C. for 90 minutes for the removal of water and fat. According to the recipe shown in Table 71, the other material was admixed with the beef to prepare a uniform mixture, which was then filled into a film bag, sterilized at 75° C. for 60 minutes and thereafter refrigerated.

                  TABLE 71                                                         ______________________________________                                         Corned beef        Control  Example                                            ______________________________________                                         Beef(pickled and boiled)                                                                          80.0     80.0                                               Fat (cow)          20.0     5.0                                                Dextrin (Example 6)                                                                               --       10.0                                               Water              --       5.0                                                Dietary fiber      0.48     4.83                                               Dietary fiber/50 g 0.24     2.42                                               Caloric val.1(KCal/100 g)                                                                         245      151                                                Caloric val.2(KCal/100 g)                                                                         245      146                                                ______________________________________                                    

Example 48

Food example 43

According to the recipe of Table 72, onions and beef were minced and mixed with all the other ingredients, and the mixture was uniformly kneaded and molded. The molded piece was griddled on iron plate at 180° C. over each side for 30 seconds, then boiled at 100° C. for 10 minutes, cooled and thereafter frozen to obtain a frozen hamburger.

                  TABLE 72                                                         ______________________________________                                         Hamburg steak      Control  Example                                            ______________________________________                                         Processed meat (minced)                                                                           38.8     38.8                                               Fat (cow)          20.0     5.0                                                Dextrin (Example 7)                                                                               --       14.0                                               Water              --       5.0                                                Onion              20.0     20.0                                               Fresh crumb        10.0     8.0                                                Starch             10.0     8.0                                                Seasonings and spices                                                                             1.2      1.2                                                Dietary fiber      0.59     4.62                                               Dietary fiber/200 g                                                                               1.18     9.24                                               Caloric val.1(KCal/100 g)                                                                         336      241                                                Caloric val.2(KCal/100 g)                                                                         336      235                                                ______________________________________                                    

Example 49

Food example 42

Hamburger putty was prepared according to the recipe of Table 73 by crushing the ingredients into a mixture, filling the mixture into a film bag having a diameter of 8 cm, thereafter freezing the mixture at -30° C. and cutting the mixture into slices, 8 mm in thickness, by a slicer.

                  TABLE 73                                                         ______________________________________                                         Hamburg putty      Control  Example                                            ______________________________________                                         Beef               50.0     50.0                                               Poke               25.0     25.0                                               Fat (cow)          10.0     10.0                                               Onion              10.0     10.0                                               Spices             0.5      0.5                                                Salt               1.0      1.0                                                Sugar              1.0      1.0                                                Egg (whole)        2.5      2.5                                                Dextrin (Example 6)                                                                               --       10.0                                               Dietary fiber      0.48     4.83                                               Dietary fiber/60 g 0.29     2.63                                               ______________________________________                                    

Example 50

Food example 43

Liver paste was prepared according to the recipe of Table 74 by boiling liver, beef and belly at 100° C. for 5 seconds, then crushing these ingredients, mixing them with the other ingredients, boiling the mixture at 80° C. with full stirring and refrigerating the mixture.

                  TABLE 74                                                         ______________________________________                                         Liver paste        Control  Example                                            ______________________________________                                         Liver              30.0     30.0                                               Beef               12.0     12.0                                               Beef (belly)       25.69    16.5                                               Lard               20.0     5.0                                                Dextrin (Example 6)                                                                               --       19.19                                              Water              --       5.0                                                Soup               8.0      8.0                                                Spices             2.3      2.3                                                Salt               2.0      2.0                                                Sodium nitrite     0.01     0.01                                               Dietary fiber      0.41     8.70                                               Dietary fiber/30 g 0.12     2.61                                               Caloric val.1(KCal/100 g)                                                                         330      214                                                Caloric val.2(KCal/100 g)                                                                         330      203                                                ______________________________________                                    

Example 51

Food example 44

The dough ingredients listed in Table 75 were fully kneaded together, then fermented at 40° C. for 30 minutes in a heat-insulated device and cut into pieces of suitable size, which were spread out with a needle rod. The ingredients for a pizza sauce were thoroughly mixed together and used after standing for at least 1 hour. The sauce was applied to pizza crust followed by baking in an oven at about 230° C. for 12 minutes to prepare pizza.

                  TABLE 75                                                         ______________________________________                                         Pizza (8 sheets)   Control  Example                                            ______________________________________                                         Hard wheat flour   250.0    250.0                                              Soft wheat flour   250.0    250.0                                              Dried yeast        10.0     10.0                                               Egg (whole)        80.0     80.0                                               Water              200.0    200.0                                              Salt               8.0      8.0                                                Olive oil          18.0     18.0                                               Sugar              2.0      2.0                                                Tomato (boiled)    400.0    400.0                                              Tomato paste       10.5     10.5                                               Garlic             15.0     15.0                                               Salt               5.2      5.2                                                Spices             2.0      2.0                                                Olive oil          30.0     30.0                                               Dextrin (Example 6)                                                                               --       60.0                                               Dietary fiber      14.1     40.2                                               Dietary fiber/sheet                                                                               1.76     5.02                                               ______________________________________                                    

Example 52

Food example 45

An omelet was prepared according to the recipe of Table 76 by dissolving indigestible dextrin in milk, admixing the solution with eggs along with the other ingredients and pan-frying the mixture in salad oil.

                  TABLE 76                                                         ______________________________________                                         Omlett             Control  Example                                            ______________________________________                                         Egg (whole)        100.0    100.0                                              Milk               30.0     30.0                                               Salt               1.0      1.0                                                Pepper             0.2      0.2                                                Salad oil          5.0      5.0                                                Butter             5.0      5.0                                                Dextrin (Example 6)                                                                               --       15.0                                               Dietary fiber      0.16     6.69                                               ______________________________________                                    

Example 53

Food example 46

The materials listed in Table 77 were crushed and mixed together in a raw state to obtain a meat pie ingredient, which was then wrapped with pie dough, followed by baking in an oven at 200° C. for about 30 minutes until the baked mass became colored by scorching to prepare a meat pie.

                  TABLE 77                                                         ______________________________________                                         Filling of meat pie                                                                               Control  Example                                            ______________________________________                                         Poke (minced)      19.1     19.1                                               Lard               23.8     6.0                                                Butter             3.0      1.5                                                Dextrin (Example 6)                                                                               --       12.6                                               Water              --       21.4                                               Milk               29.6     14.8                                               Milk flavor        --       0.1                                                Crumb              14.1     14.1                                               Egg (whole)        8.9      8.9                                                Spices             0.3      0.2                                                Salt               1.2      1.2                                                Dietary fiber      0.44     5.89                                               Dietary fiber/50 g 0.22     2.95                                               Caloric val.1(KCal/100 g)                                                                         333      205                                                Caloric val.2(KCal/100 g)                                                                         333      198                                                ______________________________________                                    

Example 54

Food example 47

A steamed Chinese dumpling stuffed with minced pork and frozen was prepared according to the recipe of Table 78 by mincing the vegetables listed, mixing them with the other materials after removal of water to obtain an inner ingredient, and wrapping the ingredient with a covering, followed by steaming at 100° C. for 5 minutes, then by cooling and thereafter by freezing.

                  TABLE 78                                                         ______________________________________                                         Filling of                                                                     Chinese dumpling   Control  Example                                            ______________________________________                                         Poke (minced)      23.5     23.5                                               Lard               10.0     5.0                                                Dextrin (Example 7)                                                                               --       2.5                                                Water              --       2.5                                                Chinese cabage     16.0     16.0                                               Cabage             22.0     22.0                                               Welsh onion        7.0      7.0                                                Onion              14.0     14.0                                               Seasonings and spices                                                                             7.5      7.5                                                Dietary fiber      0.84     1.56                                               Dietary fiber/80 g 0.67     1.25                                               Caloric val.1(KCal/100 g)                                                                         169      137                                                Caloric val.2(KCal/100 g)                                                                         169      136                                                ______________________________________                                    

Example 55

Food example 48

According to the recipe of Table 79, ground fish meat, salt and a small amount of ice were mixed together, the mixture was broken and agitated for 5 minutes by a silent cutter, and the other materials and the remaining amount of ice were added to the resulting mixture and mixed therewith for 10 minutes. When the mixture became thickened or viscous at 15° C., the mixture was molded and fried in oil at 160° C. for 4 minutes to obtain fried kamaboko.

                  TABLE 79                                                         ______________________________________                                         Kamaboko           Control  Example                                            ______________________________________                                         Surimi             60.0     60.0                                               Salt               1.8      1.8                                                Ice                30.4     30.4                                               Starch             6.0      6.0                                                Seasonings         1.8      1.8                                                Dextrin (Example 6)                                                                               --       6.0                                                Dietary fiber      0.60     3.21                                               Dietary fiber/120 g                                                                               0.72     3.63                                               ______________________________________                                    

Example 56

Food example 49

A blackberry liquor was prepared according to the recipe of Table 80 by immersing blackberries in distilled spirits for 40 days, discarding the blackberries and then aging the spirits for 2 months.

                  TABLE 80                                                         ______________________________________                                         Black berry liquor Control  Example                                            ______________________________________                                         Black berry        57.0     57.0                                               Sugar              34.2     17.1                                               Dextrin (Example 7)                                                                               --       17.0                                               Aspartame          --       0.1                                                White liquor(70 proof)                                                                            65.8     65.8                                               Dietary fiber      0        4.90                                               Dietary fiber/100 g                                                                               0        4.90                                               ______________________________________                                    

Example 57

Feed example 1

Dog food was prepared according to the recipe of Table 81.

                  TABLE 81                                                         ______________________________________                                         Dog food           Control  Example                                            ______________________________________                                         Corn               25.0     25.0                                               Wheat and wheat flour                                                                             24.0     24.0                                               Born and meat meal 16.3     16.3                                               Soy bean waste     14.4     14.4                                               Fish meal          4.8      4.8                                                Wheat germ         2.9      2.9                                                Yeast              2.9      2.9                                                Animal fat         3.8      3.8                                                Vitamins and minerals                                                                             5.9      5.9                                                Dextrin (Example 1)                                                                               --       10.0                                               Dietary fiber      4.70     7.37                                               ______________________________________                                    

Example 58

Feed example 2

Cat food was prepared according to the recipe of Table 82.

                  TABLE 82                                                         ______________________________________                                         Cat food           Control  Example                                            ______________________________________                                         Corn               28.4     28.4                                               Wheat flour        27.3     27.3                                               Brewer's yeast     3.3      3.3                                                Malt               3.3      3.3                                                Soy bean waste     16.4     16.4                                               Fish meal          0.5      0.5                                                Meat meal          18.6     18.6                                               Vitamins and minerals                                                                             2.2      2.2                                                Dextrin (Example 1)                                                                               --       10.0                                               Dietary fiber      5.43     8.10                                               ______________________________________                                    

Example 59

Feed example 3

A feed for pigs was prepared according to the recipe of Table 83.

                  TABLE 83                                                         ______________________________________                                         Pig feed           Control  Example                                            ______________________________________                                         Corn               75.0     75.0                                               Soy bean waste     11.0     11.0                                               Bran               3.0      3.0                                                Fish meal          9.0      9.0                                                Calcium tri-phosphate                                                                             0.7      0.7                                                Calcium carbonate  0.6      0.6                                                Salt               0.3      0.3                                                Vitamins           0.2      0.2                                                Minerals           0.2      0.2                                                Dextrin (Example 1)                                                                               --       10.0                                               Dietary fiber      6.95     9.62                                               ______________________________________                                    

Example 60

Feed example 4

A feed for broilers in the initial stage was prepared according to the recipe of Table 84.

                  TABLE 84                                                         ______________________________________                                         Feed for broiler   Control  Example                                            ______________________________________                                         Corn               44.65    44.65                                              Milo               10.0     10.0                                               Soy bean waste     23.0     23.0                                               Fish meal          9.0      9.0                                                Gluten meal        3.0      3.0                                                Alfalfa meal       2.0      2.0                                                Corn distiller's dried                                                                            1.0      1.0                                                solubles                                                                       Animal fat         5.1      5.1                                                Salt               0.25     0.25                                               Calcium carbonate  0.6      0.6                                                Calcium di-phosphate                                                                              0.8      0.8                                                Lysine             0.05     0.05                                               Methionine         0.18     0.18                                               Vitamins           0.1      0.1                                                Choline chloride   0.05     0.05                                               Minerals           0.1      0.1                                                Nicarbazin         0.05     0.05                                               Oxytetracycline    0.07     0.07                                               Dextrin (Example 1)                                                                               --       10.0                                               Dietary fiber      7.54     10.2                                               ______________________________________                                    

Example 61

Feed example 5

A feed for laboratory rats was prepared according to the recipe of Table 85.

                  TABLE 85                                                         ______________________________________                                         Feed for laboratory rat                                                                           Control  Example                                            ______________________________________                                         Wheat              12.4     12.4                                               Oat                18.6     18.6                                               Corn               10.3     10.3                                               Barley             34.1     34.1                                               Bran               3.1      3.1                                                Fish meal          6.3      6.3                                                Skimmed milk powder                                                                               1.0      1.0                                                Alfalfa            1.6      1.6                                                Molass             1.0      1.0                                                Vitamins and minerals                                                                             0.5      0.5                                                Others             11.1     11.1                                               Dextrin (Example 1)                                                                               --       10.0                                               Dietary fiber      6.22     8.89                                               ______________________________________                                     

What we claim is:
 1. An indigestible dextrin characterized in that the dextrin contains:(A) up to 50% of 1→4 glycosidic linkages, and (B) up to 60% of an indigestible component, (C) the content of indigestible component as actually determined varying within the range of ±5% from a value Y calculated from at least one of Equations 1, 9, 11, 17, 18, 20, 28, 29, 30 and 31, given below, (D) the indigestible dextrin being prepared by adding hydrochloric acid to potato starch and heating the potato starch at 120° to 200° C. using an extruder, the value Y being a calculated content (%) of the indigestible component in the equations given below, X1, X2, X3, X4 and X5 have the following meaning and are values quantitatively determined for the dextrin by "Hakomori's methylation method" X1: amount (%) of glucose residues at non-reducing ends X2: amount (%) of glucose residues having a 1→4 glycosidic linkage X3: amount (%) of glucose residues having a 1→4 glycosidic linkage X4: amount (%) of glucose residues having a 1→3 glycosidic linkage X5: amount (%) of glucose residues having glycosidic linkages other than the above residues, glucose residues having both 1→4 and 1→6 glycosidic linkages, glucose residues having both 1→3 and 1→4 glycosidic linkages and glucose residues having both 1→2 and 1→4 glycosidic linkages Equation 1:

    Y=-26.2+3.942·X1

Equation 9:

    Y=16+1.891·X1+5.531·X5

Equation 11:

    Y=124.5-1.11·X2-0.868·X4

Equation 17:

    Y=124.4-0.008·X1-1.106·X2-0.84·X4

Equation 18:

    Y=58.5+1.022·X1-0.404·X2+1.196·X5

Equation 20:

    Y=25+1.327·X1+0.83·X3+1.562·X5

Equation 21:

    Y=12.9+2.087·X1-0.393·X4+2.158·X5

Equation 28:

    Y=68.3+1.844·X1-0.726·X2-3.026·X4+1.594.multidot.X5

Equation 29:

    Y=-27.4+2.008·X1+0.587·X2+1.683·X3+2.289.multidot.X5

Equation 30:

    Y=1390.1+18.949·X2-23.381·X3-45.838·X4-7.775.multidot.X5

Equation 31:

    Y=59.4+1.859·X1-0.604·X2+0.156·X3-2.744.multidot.X4.


2. An indigestible dextrin as defined in claim 1 wherein the variation range from the value Y for Equations 1, 9, 11, 17, 18, 20, 21, 28, 29 and 30 is within ±2%.
 3. An indigestible dextrin as defined in claim 1 which contains:(A) up to 40% of 1→4 glycosidic linkages, and (B) at least 75% of the indigestible component.
 4. An indigestible dextrin as defined in claim 1 wherein the heating temperature is 130° C. to 180° C.
 5. An indigestible dextrin as defined in claim 1 wherein the extruder is a twin-screw extruder.
 6. An indigestible dextrin as defined in claim 1 which is a low calorie dextrin.
 7. An indigestible dextrin as defined in claim 1 which is up to 2.4 kcal/g in caloric value
 1. 8. An indigestible dextrin as defined in claim 1 which is up to 2 kcal/g in caloric value
 2. 9. An indigestible dextrin as defined in claim 3 which is up to 2.2 kcal/g in caloric value
 1. 10. An indigestible dextrin as defined in claim 3 which is up to 1.8 kcal/g in caloric value
 2. 11. An indigestible dextrin as defined in claim 1 which contains a dietary fiber.
 12. An indigestible dextrin as defined in claim 1 which contains at least 25% of a dietary fiber.
 13. An indigestible dextrin as defined in claim 3 which contains at least 30% of a dietary fiber.
 14. An indigestible dextrin as defined in claim 1 which has activity to diminish serum lipids.
 15. An indigestible dextrin as defined in claim 1 which has activity to improve the intestine.
 16. An indigestible dextrin as defined in claim 1 which has activity to reduce the secretion of insulin.
 17. An indigestible dextrin as defined in claim 1 which has hypotensive effect.
 18. An indigestible dextrin as defined in claim 1 which has activity to prevent cancer of the large intestine.
 19. A food containing an indigestible dextrin as defined in claim
 1. 20. A food as defined in claim 19 which is a candy, cake, bakery product, ice, snack, beverage or yoghurt.
 21. A food as defined in claim 19 which is a soup, mayonnaise, dressing, processed livestock meat product or processed fishery product.
 22. A food containing an indigestible dextrin as defined in claim
 8. 23. An indigestible dextrin as defined in claim 1, wherein the whiteness of the dextrin relative to the whiteness of magnesium oxide taken as 100% is at least 20.7%.
 24. A process for preparing an indigestible dextrin containing up to 50% of 1→4 glycosidic linkages and at least 60% of an indigestible component, which comprises adding hydrochloric acid to potato starch and heating the potato starch at 120° to 200° C. using an extruder.
 25. A process for preparing an indigestible dextrin as defined in claim 24, wherein the whiteness of the dextrin relative to the whiteness of magnesium oxide taken as 100% is at least 20.7%.
 26. A process for preparing an indigestible dextrin as defined in claim 24, wherein the extruder is a twin-screw extruder.
 27. A process for preparing an indigestible dextrin as defined in claim 24, wherein the heating is conducted at 130 to 180° C.
 28. An indigestible dextrin as defined in claim 1, wherein the content of indigestible component as actually determined varies within the range of ±5% from a value Y calculated from at least one of Equations 1 and
 31. 